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