1 /*-
2 * Copyright (c) 2010 David Malone <dwmalone@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/types.h>
28
29 #include <net/rss_config.h>
30 #include <net/toeplitz.h>
31
32 #include <sys/systm.h>
33
34 uint32_t
toeplitz_hash(u_int keylen,const uint8_t * key,u_int datalen,const uint8_t * data)35 toeplitz_hash(u_int keylen, const uint8_t *key, u_int datalen,
36 const uint8_t *data)
37 {
38 uint32_t hash = 0, v;
39 u_int i, b;
40
41 /* XXXRW: Perhaps an assertion about key length vs. data length? */
42
43 v = (key[0]<<24) + (key[1]<<16) + (key[2] <<8) + key[3];
44 for (i = 0; i < datalen; i++) {
45 for (b = 0; b < 8; b++) {
46 if (data[i] & (1<<(7-b)))
47 hash ^= v;
48 v <<= 1;
49 if ((i + 4) < RSS_KEYSIZE &&
50 (key[i+4] & (1<<(7-b))))
51 v |= 1;
52 }
53 }
54 return (hash);
55 }
56