Commit fed85383 authored by YOSHIFUJI Hideaki's avatar YOSHIFUJI Hideaki
Browse files

[IPV6]: Use XOR and OR rather than mutiple ands for ipv6 address comparisons. 



ipv6_addr_equal(), ipv6_addr_v4mapped(),
ipv6_addr_is_ll_all_{nodes,routers}(),
ipv6_masked_addr_cmp()

Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
parent caad295f

include/net/addrconf.h

+6 −8
Original line number Diff line number Diff line
@@ -240,18 +240,16 @@ static inline int ipv6_addr_is_multicast(const struct in6_addr *addr) 


static inline int ipv6_addr_is_ll_all_nodes(const struct in6_addr *addr)

{

	return (addr->s6_addr32[0] == htonl(0xff020000) &&

		addr->s6_addr32[1] == 0 &&

		addr->s6_addr32[2] == 0 &&

		addr->s6_addr32[3] == htonl(0x00000001));

	return (((addr->s6_addr32[0] ^ htonl(0xff020000)) |

		addr->s6_addr32[1] | addr->s6_addr32[2] |

		(addr->s6_addr32[3] ^ htonl(0x00000001))) == 0);

}



static inline int ipv6_addr_is_ll_all_routers(const struct in6_addr *addr)

{

	return (addr->s6_addr32[0] == htonl(0xff020000) &&

		addr->s6_addr32[1] == 0 &&

		addr->s6_addr32[2] == 0 &&

		addr->s6_addr32[3] == htonl(0x00000002));

	return (((addr->s6_addr32[0] ^ htonl(0xff020000)) |

		addr->s6_addr32[1] | addr->s6_addr32[2] |

		(addr->s6_addr32[3] ^ htonl(0x00000002))) == 0);

}



static inline int ipv6_isatap_eui64(u8 *eui, __be32 addr)

include/net/ipv6.h

+10 −12
Original line number Diff line number Diff line
@@ -280,12 +280,10 @@ static inline int 
ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,

		     const struct in6_addr *a2)

{

	unsigned int i;



	for (i = 0; i < 4; i++)

		if ((a1->s6_addr32[i] ^ a2->s6_addr32[i]) & m->s6_addr32[i])

			return 1;

	return 0;

	return (!!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |

		   ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |

		   ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |

		   ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3])));

}



static inline void ipv6_addr_copy(struct in6_addr *a1, const struct in6_addr *a2)
@@ -320,10 +318,10 @@ static inline void ipv6_addr_set(struct in6_addr *addr, 
static inline int ipv6_addr_equal(const struct in6_addr *a1,

				  const struct in6_addr *a2)

{

	return (a1->s6_addr32[0] == a2->s6_addr32[0] &&

		a1->s6_addr32[1] == a2->s6_addr32[1] &&

		a1->s6_addr32[2] == a2->s6_addr32[2] &&

		a1->s6_addr32[3] == a2->s6_addr32[3]);

	return (((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |

		 (a1->s6_addr32[1] ^ a2->s6_addr32[1]) |

		 (a1->s6_addr32[2] ^ a2->s6_addr32[2]) |

		 (a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0);

}



static inline int __ipv6_prefix_equal(const __be32 *a1, const __be32 *a2,
@@ -371,8 +369,8 @@ static inline int ipv6_addr_any(const struct in6_addr *a) 


static inline int ipv6_addr_v4mapped(const struct in6_addr *a)

{

	return ((a->s6_addr32[0] | a->s6_addr32[1]) == 0 &&

		 a->s6_addr32[2] == htonl(0x0000ffff));

	return ((a->s6_addr32[0] | a->s6_addr32[1] |

		 (a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0);

}



/*