android_kernel_samsung_msm8976/net/ipv4/netfilter/ipt_MARK.c
Harald Welte 6869c4d8e0 [NETFILTER]: reduce netfilter sk_buff enlargement
As discussed at netconf'05, we're trying to save every bit in sk_buff.
The patch below makes sk_buff 8 bytes smaller.  I did some basic
testing on my notebook and it seems to work.

The only real in-tree user of nfcache was IPVS, who only needs a
single bit.  Unfortunately I couldn't find some other free bit in
sk_buff to stuff that bit into, so I introduced a separate field for
them.  Maybe the IPVS guys can resolve that to further save space.

Initially I wanted to shrink pkt_type to three bits (PACKET_HOST and
alike are only 6 values defined), but unfortunately the bluetooth code
overloads pkt_type :(

The conntrack-event-api (out-of-tree) uses nfcache, but Rusty just
came up with a way how to do it without any skb fields, so it's safe
to remove it.

- remove all never-implemented 'nfcache' code
- don't have ipvs code abuse 'nfcache' field. currently get's their own
  compile-conditional skb->ipvs_property field.  IPVS maintainers can
  decide to move this bit elswhere, but nfcache needs to die.
- remove skb->nfcache field to save 4 bytes
- move skb->nfctinfo into three unused bits to save further 4 bytes

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:31:04 -07:00

172 lines
3.8 KiB
C

/* This is a module which is used for setting the NFMARK field of an skb. */
/* (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
*
* 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/checksum.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_MARK.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_DESCRIPTION("iptables MARK modification module");
static unsigned int
target_v0(struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const void *targinfo,
void *userinfo)
{
const struct ipt_mark_target_info *markinfo = targinfo;
if((*pskb)->nfmark != markinfo->mark)
(*pskb)->nfmark = markinfo->mark;
return IPT_CONTINUE;
}
static unsigned int
target_v1(struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const void *targinfo,
void *userinfo)
{
const struct ipt_mark_target_info_v1 *markinfo = targinfo;
int mark = 0;
switch (markinfo->mode) {
case IPT_MARK_SET:
mark = markinfo->mark;
break;
case IPT_MARK_AND:
mark = (*pskb)->nfmark & markinfo->mark;
break;
case IPT_MARK_OR:
mark = (*pskb)->nfmark | markinfo->mark;
break;
}
if((*pskb)->nfmark != mark)
(*pskb)->nfmark = mark;
return IPT_CONTINUE;
}
static int
checkentry_v0(const char *tablename,
const struct ipt_entry *e,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
struct ipt_mark_target_info *markinfo = targinfo;
if (targinfosize != IPT_ALIGN(sizeof(struct ipt_mark_target_info))) {
printk(KERN_WARNING "MARK: targinfosize %u != %Zu\n",
targinfosize,
IPT_ALIGN(sizeof(struct ipt_mark_target_info)));
return 0;
}
if (strcmp(tablename, "mangle") != 0) {
printk(KERN_WARNING "MARK: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
return 0;
}
if (markinfo->mark > 0xffffffff) {
printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
return 0;
}
return 1;
}
static int
checkentry_v1(const char *tablename,
const struct ipt_entry *e,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
struct ipt_mark_target_info_v1 *markinfo = targinfo;
if (targinfosize != IPT_ALIGN(sizeof(struct ipt_mark_target_info_v1))){
printk(KERN_WARNING "MARK: targinfosize %u != %Zu\n",
targinfosize,
IPT_ALIGN(sizeof(struct ipt_mark_target_info_v1)));
return 0;
}
if (strcmp(tablename, "mangle") != 0) {
printk(KERN_WARNING "MARK: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
return 0;
}
if (markinfo->mode != IPT_MARK_SET
&& markinfo->mode != IPT_MARK_AND
&& markinfo->mode != IPT_MARK_OR) {
printk(KERN_WARNING "MARK: unknown mode %u\n",
markinfo->mode);
return 0;
}
if (markinfo->mark > 0xffffffff) {
printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
return 0;
}
return 1;
}
static struct ipt_target ipt_mark_reg_v0 = {
.name = "MARK",
.target = target_v0,
.checkentry = checkentry_v0,
.me = THIS_MODULE,
.revision = 0,
};
static struct ipt_target ipt_mark_reg_v1 = {
.name = "MARK",
.target = target_v1,
.checkentry = checkentry_v1,
.me = THIS_MODULE,
.revision = 1,
};
static int __init init(void)
{
int err;
err = ipt_register_target(&ipt_mark_reg_v0);
if (!err) {
err = ipt_register_target(&ipt_mark_reg_v1);
if (err)
ipt_unregister_target(&ipt_mark_reg_v0);
}
return err;
}
static void __exit fini(void)
{
ipt_unregister_target(&ipt_mark_reg_v0);
ipt_unregister_target(&ipt_mark_reg_v1);
}
module_init(init);
module_exit(fini);