netfilter: factorize ifname_compare()

We use same not trivial helper function in four places. We can factorize it.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Eric Dumazet 2009-03-25 17:31:52 +01:00 committed by Patrick McHardy
parent 78f3648601
commit b8dfe49877
5 changed files with 30 additions and 74 deletions

View File

@ -435,6 +435,29 @@ extern void xt_free_table_info(struct xt_table_info *info);
extern void xt_table_entry_swap_rcu(struct xt_table_info *old,
struct xt_table_info *new);
/*
* This helper is performance critical and must be inlined
*/
static inline unsigned long ifname_compare_aligned(const char *_a,
const char *_b,
const char *_mask)
{
const unsigned long *a = (const unsigned long *)_a;
const unsigned long *b = (const unsigned long *)_b;
const unsigned long *mask = (const unsigned long *)_mask;
unsigned long ret;
ret = (a[0] ^ b[0]) & mask[0];
if (IFNAMSIZ > sizeof(unsigned long))
ret |= (a[1] ^ b[1]) & mask[1];
if (IFNAMSIZ > 2 * sizeof(unsigned long))
ret |= (a[2] ^ b[2]) & mask[2];
if (IFNAMSIZ > 3 * sizeof(unsigned long))
ret |= (a[3] ^ b[3]) & mask[3];
BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
return ret;
}
#ifdef CONFIG_COMPAT
#include <net/compat.h>

View File

@ -80,19 +80,7 @@ static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask)
{
#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
const unsigned long *a = (const unsigned long *)_a;
const unsigned long *b = (const unsigned long *)_b;
const unsigned long *mask = (const unsigned long *)_mask;
unsigned long ret;
ret = (a[0] ^ b[0]) & mask[0];
if (IFNAMSIZ > sizeof(unsigned long))
ret |= (a[1] ^ b[1]) & mask[1];
if (IFNAMSIZ > 2 * sizeof(unsigned long))
ret |= (a[2] ^ b[2]) & mask[2];
if (IFNAMSIZ > 3 * sizeof(unsigned long))
ret |= (a[3] ^ b[3]) & mask[3];
BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
unsigned long ret = ifname_compare_aligned(_a, _b, _mask);
#else
unsigned long ret = 0;
int i;

View File

@ -74,25 +74,6 @@ do { \
Hence the start of any table is given by get_table() below. */
static unsigned long ifname_compare(const char *_a, const char *_b,
const unsigned char *_mask)
{
const unsigned long *a = (const unsigned long *)_a;
const unsigned long *b = (const unsigned long *)_b;
const unsigned long *mask = (const unsigned long *)_mask;
unsigned long ret;
ret = (a[0] ^ b[0]) & mask[0];
if (IFNAMSIZ > sizeof(unsigned long))
ret |= (a[1] ^ b[1]) & mask[1];
if (IFNAMSIZ > 2 * sizeof(unsigned long))
ret |= (a[2] ^ b[2]) & mask[2];
if (IFNAMSIZ > 3 * sizeof(unsigned long))
ret |= (a[3] ^ b[3]) & mask[3];
BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
return ret;
}
/* Returns whether matches rule or not. */
/* Performance critical - called for every packet */
static inline bool
@ -121,7 +102,7 @@ ip_packet_match(const struct iphdr *ip,
return false;
}
ret = ifname_compare(indev, ipinfo->iniface, ipinfo->iniface_mask);
ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask);
if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
dprintf("VIA in mismatch (%s vs %s).%s\n",
@ -130,7 +111,7 @@ ip_packet_match(const struct iphdr *ip,
return false;
}
ret = ifname_compare(outdev, ipinfo->outiface, ipinfo->outiface_mask);
ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask);
if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
dprintf("VIA out mismatch (%s vs %s).%s\n",

View File

@ -89,25 +89,6 @@ ip6t_ext_hdr(u8 nexthdr)
(nexthdr == IPPROTO_DSTOPTS) );
}
static unsigned long ifname_compare(const char *_a, const char *_b,
const unsigned char *_mask)
{
const unsigned long *a = (const unsigned long *)_a;
const unsigned long *b = (const unsigned long *)_b;
const unsigned long *mask = (const unsigned long *)_mask;
unsigned long ret;
ret = (a[0] ^ b[0]) & mask[0];
if (IFNAMSIZ > sizeof(unsigned long))
ret |= (a[1] ^ b[1]) & mask[1];
if (IFNAMSIZ > 2 * sizeof(unsigned long))
ret |= (a[2] ^ b[2]) & mask[2];
if (IFNAMSIZ > 3 * sizeof(unsigned long))
ret |= (a[3] ^ b[3]) & mask[3];
BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
return ret;
}
/* Returns whether matches rule or not. */
/* Performance critical - called for every packet */
static inline bool
@ -138,7 +119,7 @@ ip6_packet_match(const struct sk_buff *skb,
return false;
}
ret = ifname_compare(indev, ip6info->iniface, ip6info->iniface_mask);
ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask);
if (FWINV(ret != 0, IP6T_INV_VIA_IN)) {
dprintf("VIA in mismatch (%s vs %s).%s\n",
@ -147,7 +128,7 @@ ip6_packet_match(const struct sk_buff *skb,
return false;
}
ret = ifname_compare(outdev, ip6info->outiface, ip6info->outiface_mask);
ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask);
if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) {
dprintf("VIA out mismatch (%s vs %s).%s\n",

View File

@ -20,23 +20,6 @@ MODULE_DESCRIPTION("Xtables: Bridge physical device match");
MODULE_ALIAS("ipt_physdev");
MODULE_ALIAS("ip6t_physdev");
static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask)
{
const unsigned long *a = (const unsigned long *)_a;
const unsigned long *b = (const unsigned long *)_b;
const unsigned long *mask = (const unsigned long *)_mask;
unsigned long ret;
ret = (a[0] ^ b[0]) & mask[0];
if (IFNAMSIZ > sizeof(unsigned long))
ret |= (a[1] ^ b[1]) & mask[1];
if (IFNAMSIZ > 2 * sizeof(unsigned long))
ret |= (a[2] ^ b[2]) & mask[2];
if (IFNAMSIZ > 3 * sizeof(unsigned long))
ret |= (a[3] ^ b[3]) & mask[3];
BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
return ret;
}
static bool
physdev_mt(const struct sk_buff *skb, const struct xt_match_param *par)
@ -85,7 +68,7 @@ physdev_mt(const struct sk_buff *skb, const struct xt_match_param *par)
if (!(info->bitmask & XT_PHYSDEV_OP_IN))
goto match_outdev;
indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname;
ret = ifname_compare(indev, info->physindev, info->in_mask);
ret = ifname_compare_aligned(indev, info->physindev, info->in_mask);
if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN))
return false;
@ -95,7 +78,7 @@ match_outdev:
return true;
outdev = nf_bridge->physoutdev ?
nf_bridge->physoutdev->name : nulldevname;
ret = ifname_compare(outdev, info->physoutdev, info->out_mask);
ret = ifname_compare_aligned(outdev, info->physoutdev, info->out_mask);
return (!!ret ^ !(info->invert & XT_PHYSDEV_OP_OUT));
}