67 lines
2.3 KiB
C++
67 lines
2.3 KiB
C++
/*-
|
|
* Copyright (c) 2010 David Malone <dwmalone@FreeBSD.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef TOEPLITZ_HH_
|
|
#define TOEPLITZ_HH_
|
|
|
|
#include <array>
|
|
|
|
constexpr size_t rss_keysize = 40;
|
|
using rss_key_type = std::array<uint8_t, rss_keysize>;
|
|
|
|
// Mellanox Linux's driver key in network byte order
|
|
static const rss_key_type rsskey = { {
|
|
0xd1,0x81,0xc6,0x2c,0xf7,0xf4,0xdb,0x5b,
|
|
0x19,0x83,0xa2,0xfc,0x94,0x3e,0x1a,0xdb,
|
|
0xd9,0x38,0x9e,0x6b,0xd1,0x03,0x9c,0x2c,
|
|
0xa7,0x44,0x99,0xad,0x59,0x3d,0x56,0xd9,
|
|
0xf3,0x25,0x3c,0x06,0x2a,0xdc,0x1f,0xfc
|
|
} };
|
|
|
|
template<typename T>
|
|
static inline uint32_t
|
|
toeplitz_hash(const rss_key_type& key, const T& data)
|
|
{
|
|
uint32_t hash = 0, v;
|
|
u_int i, b;
|
|
|
|
/* XXXRW: Perhaps an assertion about key length vs. data length? */
|
|
|
|
v = (key[0]<<24) + (key[1]<<16) + (key[2] <<8) + key[3];
|
|
for (i = 0; i < data.size(); i++) {
|
|
for (b = 0; b < 8; b++) {
|
|
if (data[i] & (1<<(7-b)))
|
|
hash ^= v;
|
|
v <<= 1;
|
|
if ((i + 4) < key.size() &&
|
|
(key[i+4] & (1<<(7-b))))
|
|
v |= 1;
|
|
}
|
|
}
|
|
return (hash);
|
|
}
|
|
#endif
|