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Commit b8dfe498 authored by Eric Dumazet's avatar Eric Dumazet Committed by Patrick McHardy
Browse files

netfilter: factorize ifname_compare() 



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

Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 78f36486

include/linux/netfilter/x_tables.h

+23 −0
Original line number Diff line number Diff line
@@ -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>

net/ipv4/netfilter/arp_tables.c

+1 −13
Original line number Diff line number Diff line
@@ -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;

net/ipv4/netfilter/ip_tables.c

+2 −21
Original line number Diff line number Diff line
@@ -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",

net/ipv6/netfilter/ip6_tables.c

+2 −21
Original line number Diff line number Diff line
@@ -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",

net/netfilter/xt_physdev.c

+2 −19
Original line number Diff line number Diff line
@@ -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 @@ physdev_mt(const struct sk_buff *skb, const struct xt_match_param *par) 
		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));

}