xref: /xnu-11417.121.6/bsd/net/flowhash.h (revision a1e26a70f38d1d7daa7b49b258e2f8538ad81650)
1*a1e26a70SApple OSS Distributions /*
2*a1e26a70SApple OSS Distributions  * Copyright (c) 2011 Apple Inc. All rights reserved.
3*a1e26a70SApple OSS Distributions  *
4*a1e26a70SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*a1e26a70SApple OSS Distributions  *
6*a1e26a70SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*a1e26a70SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*a1e26a70SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*a1e26a70SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*a1e26a70SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*a1e26a70SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*a1e26a70SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*a1e26a70SApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*a1e26a70SApple OSS Distributions  *
15*a1e26a70SApple OSS Distributions  * Please obtain a copy of the License at
16*a1e26a70SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*a1e26a70SApple OSS Distributions  *
18*a1e26a70SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*a1e26a70SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*a1e26a70SApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*a1e26a70SApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*a1e26a70SApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*a1e26a70SApple OSS Distributions  * Please see the License for the specific language governing rights and
24*a1e26a70SApple OSS Distributions  * limitations under the License.
25*a1e26a70SApple OSS Distributions  *
26*a1e26a70SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*a1e26a70SApple OSS Distributions  */
28*a1e26a70SApple OSS Distributions 
29*a1e26a70SApple OSS Distributions #ifndef _NET_FLOWHASH_H_
30*a1e26a70SApple OSS Distributions #define _NET_FLOWHASH_H_
31*a1e26a70SApple OSS Distributions 
32*a1e26a70SApple OSS Distributions #include <sys/types.h>
33*a1e26a70SApple OSS Distributions 
34*a1e26a70SApple OSS Distributions #ifdef  __cplusplus
35*a1e26a70SApple OSS Distributions extern "C" {
36*a1e26a70SApple OSS Distributions #endif
37*a1e26a70SApple OSS Distributions 
38*a1e26a70SApple OSS Distributions /*
39*a1e26a70SApple OSS Distributions  * If 32-bit hash value is too large, use this macro to truncate
40*a1e26a70SApple OSS Distributions  * it to n-bit; masking is a faster operation than modulus.
41*a1e26a70SApple OSS Distributions  */
42*a1e26a70SApple OSS Distributions #define HASHMASK(n)     ((1UL << (n)) - 1)
43*a1e26a70SApple OSS Distributions 
44*a1e26a70SApple OSS Distributions /*
45*a1e26a70SApple OSS Distributions  * Returns 32-bit hash value.  Hashes which are capable of returning
46*a1e26a70SApple OSS Distributions  * more bits currently have their results truncated to 32-bit.
47*a1e26a70SApple OSS Distributions  */
48*a1e26a70SApple OSS Distributions typedef u_int32_t net_flowhash_fn_t(const void *__sized_by(len) key, u_int32_t len, const u_int32_t);
49*a1e26a70SApple OSS Distributions 
50*a1e26a70SApple OSS Distributions extern net_flowhash_fn_t *net_flowhash;
51*a1e26a70SApple OSS Distributions extern net_flowhash_fn_t net_flowhash_mh3_x86_32;
52*a1e26a70SApple OSS Distributions extern net_flowhash_fn_t net_flowhash_mh3_x64_128;
53*a1e26a70SApple OSS Distributions extern net_flowhash_fn_t net_flowhash_jhash;
54*a1e26a70SApple OSS Distributions #ifdef  __cplusplus
55*a1e26a70SApple OSS Distributions }
56*a1e26a70SApple OSS Distributions #endif
57*a1e26a70SApple OSS Distributions 
58*a1e26a70SApple OSS Distributions #endif /* _NET_FLOWHASH_H_ */
59