Seastar
High performance C++ framework for concurrent servers
All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Modules Pages
toeplitz.hh
1/*
2 * This file is open source software, licensed to you under the terms
3 * of the Apache License, Version 2.0 (the "License"). See the NOTICE file
4 * distributed with this work for additional information regarding copyright
5 * ownership. You may not use this file except in compliance with the License.
6 *
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing,
12 * software distributed under the License is distributed on an
13 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14 * KIND, either express or implied. See the License for the
15 * specific language governing permissions and limitations
16 * under the License.
17 */
18/*-
19 * Copyright (c) 2010 David Malone <dwmalone@FreeBSD.org>
20 * All rights reserved.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
32 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
35 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41 * SUCH DAMAGE.
42 */
43
44#pragma once
45
46#ifndef SEASTAR_MODULE
47#include <cstdint>
48#include <string_view>
49#include <vector>
50#endif
51
52namespace seastar {
53
54using rss_key_type = std::basic_string_view<uint8_t>;
55
56// Mellanox Linux's driver key
57static constexpr uint8_t default_rsskey_40bytes_v[] = {
58 0xd1, 0x81, 0xc6, 0x2c, 0xf7, 0xf4, 0xdb, 0x5b,
59 0x19, 0x83, 0xa2, 0xfc, 0x94, 0x3e, 0x1a, 0xdb,
60 0xd9, 0x38, 0x9e, 0x6b, 0xd1, 0x03, 0x9c, 0x2c,
61 0xa7, 0x44, 0x99, 0xad, 0x59, 0x3d, 0x56, 0xd9,
62 0xf3, 0x25, 0x3c, 0x06, 0x2a, 0xdc, 0x1f, 0xfc
63};
64
65static constexpr rss_key_type default_rsskey_40bytes{default_rsskey_40bytes_v, sizeof(default_rsskey_40bytes_v)};
66
67// Intel's i40e PMD default RSS key
68static constexpr uint8_t default_rsskey_52bytes_v[] = {
69 0x44, 0x39, 0x79, 0x6b, 0xb5, 0x4c, 0x50, 0x23,
70 0xb6, 0x75, 0xea, 0x5b, 0x12, 0x4f, 0x9f, 0x30,
71 0xb8, 0xa2, 0xc0, 0x3d, 0xdf, 0xdc, 0x4d, 0x02,
72 0xa0, 0x8c, 0x9b, 0x33, 0x4a, 0xf6, 0x4a, 0x4c,
73 0x05, 0xc6, 0xfa, 0x34, 0x39, 0x58, 0xd8, 0x55,
74 0x7d, 0x99, 0x58, 0x3a, 0xe1, 0x38, 0xc9, 0x2e,
75 0x81, 0x15, 0x03, 0x66
76};
77
78static constexpr rss_key_type default_rsskey_52bytes{default_rsskey_52bytes_v, sizeof(default_rsskey_52bytes_v)};
79
80template<typename T>
81inline uint32_t
82toeplitz_hash(rss_key_type key, const T& data)
83{
84 uint32_t hash = 0, v;
85
86 /* XXXRW: Perhaps an assertion about key length vs. data length? */
87
88 v = (key[0]<<24) + (key[1]<<16) + (key[2] <<8) + key[3];
89 for (unsigned i = 0; i < data.size(); i++) {
90 for (unsigned b = 0; b < 8; b++) {
91 if (data[i] & (1<<(7-b)))
92 hash ^= v;
93 v <<= 1;
94 if ((i + 4) < key.size() &&
95 (key[i+4] & (1<<(7-b))))
96 v |= 1;
97 }
98 }
99 return (hash);
100}
101
102}
Seastar API namespace.
Definition: abort_on_ebadf.hh:26