From 633b62df0104203591d5c427f6769857571b2540 Mon Sep 17 00:00:00 2001 From: "/C=EU/ST=EU/CN=Jozsef Kadlecsik/emailAddress=kadlec@blackhole.kfki.hu" Date: Wed, 2 Jul 2008 12:20:18 +0000 Subject: Initial ipset release with kernel modules included. --- kernel/include/linux/netfilter_ipv4/ip_set_jhash.h | 148 +++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 kernel/include/linux/netfilter_ipv4/ip_set_jhash.h (limited to 'kernel/include/linux/netfilter_ipv4/ip_set_jhash.h') diff --git a/kernel/include/linux/netfilter_ipv4/ip_set_jhash.h b/kernel/include/linux/netfilter_ipv4/ip_set_jhash.h new file mode 100644 index 0000000..25c6b97 --- /dev/null +++ b/kernel/include/linux/netfilter_ipv4/ip_set_jhash.h @@ -0,0 +1,148 @@ +#ifndef _LINUX_IPSET_JHASH_H +#define _LINUX_IPSET_JHASH_H + +/* This is a copy of linux/jhash.h but the types u32/u8 are changed + * to __u32/__u8 so that the header file can be included into + * userspace code as well. Jozsef Kadlecsik (kadlec@blackhole.kfki.hu) + */ + +/* jhash.h: Jenkins hash support. + * + * Copyright (C) 1996 Bob Jenkins (bob_jenkins@burtleburtle.net) + * + * http://burtleburtle.net/bob/hash/ + * + * These are the credits from Bob's sources: + * + * lookup2.c, by Bob Jenkins, December 1996, Public Domain. + * hash(), hash2(), hash3, and mix() are externally useful functions. + * Routines to test the hash are included if SELF_TEST is defined. + * You can use this free for any purpose. It has no warranty. + * + * Copyright (C) 2003 David S. Miller (davem@redhat.com) + * + * I've modified Bob's hash to be useful in the Linux kernel, and + * any bugs present are surely my fault. -DaveM + */ + +/* NOTE: Arguments are modified. */ +#define __jhash_mix(a, b, c) \ +{ \ + a -= b; a -= c; a ^= (c>>13); \ + b -= c; b -= a; b ^= (a<<8); \ + c -= a; c -= b; c ^= (b>>13); \ + a -= b; a -= c; a ^= (c>>12); \ + b -= c; b -= a; b ^= (a<<16); \ + c -= a; c -= b; c ^= (b>>5); \ + a -= b; a -= c; a ^= (c>>3); \ + b -= c; b -= a; b ^= (a<<10); \ + c -= a; c -= b; c ^= (b>>15); \ +} + +/* The golden ration: an arbitrary value */ +#define JHASH_GOLDEN_RATIO 0x9e3779b9 + +/* The most generic version, hashes an arbitrary sequence + * of bytes. No alignment or length assumptions are made about + * the input key. + */ +static inline __u32 jhash(void *key, __u32 length, __u32 initval) +{ + __u32 a, b, c, len; + __u8 *k = key; + + len = length; + a = b = JHASH_GOLDEN_RATIO; + c = initval; + + while (len >= 12) { + a += (k[0] +((__u32)k[1]<<8) +((__u32)k[2]<<16) +((__u32)k[3]<<24)); + b += (k[4] +((__u32)k[5]<<8) +((__u32)k[6]<<16) +((__u32)k[7]<<24)); + c += (k[8] +((__u32)k[9]<<8) +((__u32)k[10]<<16)+((__u32)k[11]<<24)); + + __jhash_mix(a,b,c); + + k += 12; + len -= 12; + } + + c += length; + switch (len) { + case 11: c += ((__u32)k[10]<<24); + case 10: c += ((__u32)k[9]<<16); + case 9 : c += ((__u32)k[8]<<8); + case 8 : b += ((__u32)k[7]<<24); + case 7 : b += ((__u32)k[6]<<16); + case 6 : b += ((__u32)k[5]<<8); + case 5 : b += k[4]; + case 4 : a += ((__u32)k[3]<<24); + case 3 : a += ((__u32)k[2]<<16); + case 2 : a += ((__u32)k[1]<<8); + case 1 : a += k[0]; + }; + + __jhash_mix(a,b,c); + + return c; +} + +/* A special optimized version that handles 1 or more of __u32s. + * The length parameter here is the number of __u32s in the key. + */ +static inline __u32 jhash2(__u32 *k, __u32 length, __u32 initval) +{ + __u32 a, b, c, len; + + a = b = JHASH_GOLDEN_RATIO; + c = initval; + len = length; + + while (len >= 3) { + a += k[0]; + b += k[1]; + c += k[2]; + __jhash_mix(a, b, c); + k += 3; len -= 3; + } + + c += length * 4; + + switch (len) { + case 2 : b += k[1]; + case 1 : a += k[0]; + }; + + __jhash_mix(a,b,c); + + return c; +} + + +/* A special ultra-optimized versions that knows they are hashing exactly + * 3, 2 or 1 word(s). + * + * NOTE: In partilar the "c += length; __jhash_mix(a,b,c);" normally + * done at the end is not done here. + */ +static inline __u32 jhash_3words(__u32 a, __u32 b, __u32 c, __u32 initval) +{ + a += JHASH_GOLDEN_RATIO; + b += JHASH_GOLDEN_RATIO; + c += initval; + + __jhash_mix(a, b, c); + + return c; +} + +static inline __u32 jhash_2words(__u32 a, __u32 b, __u32 initval) +{ + return jhash_3words(a, b, 0, initval); +} + +static inline __u32 jhash_1word(__u32 a, __u32 initval) +{ + return jhash_3words(a, 0, 0, initval); +} + +#endif /* _LINUX_IPSET_JHASH_H */ -- cgit v1.2.3