xref: /xnu-10002.1.13/bsd/net/flowhash.h (revision 1031c584a5e37aff177559b9f69dbd3c8c3fd30a)
1*1031c584SApple OSS Distributions /*
2*1031c584SApple OSS Distributions  * Copyright (c) 2011 Apple Inc. All rights reserved.
3*1031c584SApple OSS Distributions  *
4*1031c584SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*1031c584SApple OSS Distributions  *
6*1031c584SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*1031c584SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*1031c584SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*1031c584SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*1031c584SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*1031c584SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*1031c584SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*1031c584SApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*1031c584SApple OSS Distributions  *
15*1031c584SApple OSS Distributions  * Please obtain a copy of the License at
16*1031c584SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*1031c584SApple OSS Distributions  *
18*1031c584SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*1031c584SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*1031c584SApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*1031c584SApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*1031c584SApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*1031c584SApple OSS Distributions  * Please see the License for the specific language governing rights and
24*1031c584SApple OSS Distributions  * limitations under the License.
25*1031c584SApple OSS Distributions  *
26*1031c584SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*1031c584SApple OSS Distributions  */
28*1031c584SApple OSS Distributions 
29*1031c584SApple OSS Distributions #ifndef _NET_FLOWHASH_H_
30*1031c584SApple OSS Distributions #define _NET_FLOWHASH_H_
31*1031c584SApple OSS Distributions 
32*1031c584SApple OSS Distributions #include <sys/types.h>
33*1031c584SApple OSS Distributions 
34*1031c584SApple OSS Distributions #ifdef  __cplusplus
35*1031c584SApple OSS Distributions extern "C" {
36*1031c584SApple OSS Distributions #endif
37*1031c584SApple OSS Distributions 
38*1031c584SApple OSS Distributions /*
39*1031c584SApple OSS Distributions  * If 32-bit hash value is too large, use this macro to truncate
40*1031c584SApple OSS Distributions  * it to n-bit; masking is a faster operation than modulus.
41*1031c584SApple OSS Distributions  */
42*1031c584SApple OSS Distributions #define HASHMASK(n)     ((1UL << (n)) - 1)
43*1031c584SApple OSS Distributions 
44*1031c584SApple OSS Distributions /*
45*1031c584SApple OSS Distributions  * Returns 32-bit hash value.  Hashes which are capable of returning
46*1031c584SApple OSS Distributions  * more bits currently have their results truncated to 32-bit.
47*1031c584SApple OSS Distributions  */
48*1031c584SApple OSS Distributions typedef u_int32_t net_flowhash_fn_t(const void *, u_int32_t, const u_int32_t);
49*1031c584SApple OSS Distributions 
50*1031c584SApple OSS Distributions extern net_flowhash_fn_t *net_flowhash;
51*1031c584SApple OSS Distributions extern net_flowhash_fn_t net_flowhash_mh3_x86_32;
52*1031c584SApple OSS Distributions extern net_flowhash_fn_t net_flowhash_mh3_x64_128;
53*1031c584SApple OSS Distributions extern net_flowhash_fn_t net_flowhash_jhash;
54*1031c584SApple OSS Distributions #ifdef  __cplusplus
55*1031c584SApple OSS Distributions }
56*1031c584SApple OSS Distributions #endif
57*1031c584SApple OSS Distributions 
58*1031c584SApple OSS Distributions #endif /* _NET_FLOWHASH_H_ */
59