1*a9643ea8Slogwang /*-
2*a9643ea8Slogwang * Copyright (c) 2010 David Malone <[email protected]>
3*a9643ea8Slogwang * All rights reserved.
4*a9643ea8Slogwang *
5*a9643ea8Slogwang * Redistribution and use in source and binary forms, with or without
6*a9643ea8Slogwang * modification, are permitted provided that the following conditions
7*a9643ea8Slogwang * are met:
8*a9643ea8Slogwang * 1. Redistributions of source code must retain the above copyright
9*a9643ea8Slogwang * notice, this list of conditions and the following disclaimer.
10*a9643ea8Slogwang * 2. Redistributions in binary form must reproduce the above copyright
11*a9643ea8Slogwang * notice, this list of conditions and the following disclaimer in the
12*a9643ea8Slogwang * documentation and/or other materials provided with the distribution.
13*a9643ea8Slogwang *
14*a9643ea8Slogwang * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15*a9643ea8Slogwang * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*a9643ea8Slogwang * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*a9643ea8Slogwang * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*a9643ea8Slogwang * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*a9643ea8Slogwang * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*a9643ea8Slogwang * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*a9643ea8Slogwang * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*a9643ea8Slogwang * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*a9643ea8Slogwang * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*a9643ea8Slogwang * SUCH DAMAGE.
25*a9643ea8Slogwang */
26*a9643ea8Slogwang
27*a9643ea8Slogwang #include <sys/cdefs.h>
28*a9643ea8Slogwang __FBSDID("$FreeBSD$");
29*a9643ea8Slogwang
30*a9643ea8Slogwang #include <sys/types.h>
31*a9643ea8Slogwang
32*a9643ea8Slogwang #include <net/rss_config.h>
33*a9643ea8Slogwang #include <net/toeplitz.h>
34*a9643ea8Slogwang
35*a9643ea8Slogwang #include <sys/systm.h>
36*a9643ea8Slogwang
37*a9643ea8Slogwang uint32_t
toeplitz_hash(u_int keylen,const uint8_t * key,u_int datalen,const uint8_t * data)38*a9643ea8Slogwang toeplitz_hash(u_int keylen, const uint8_t *key, u_int datalen,
39*a9643ea8Slogwang const uint8_t *data)
40*a9643ea8Slogwang {
41*a9643ea8Slogwang uint32_t hash = 0, v;
42*a9643ea8Slogwang u_int i, b;
43*a9643ea8Slogwang
44*a9643ea8Slogwang /* XXXRW: Perhaps an assertion about key length vs. data length? */
45*a9643ea8Slogwang
46*a9643ea8Slogwang v = (key[0]<<24) + (key[1]<<16) + (key[2] <<8) + key[3];
47*a9643ea8Slogwang for (i = 0; i < datalen; i++) {
48*a9643ea8Slogwang for (b = 0; b < 8; b++) {
49*a9643ea8Slogwang if (data[i] & (1<<(7-b)))
50*a9643ea8Slogwang hash ^= v;
51*a9643ea8Slogwang v <<= 1;
52*a9643ea8Slogwang if ((i + 4) < RSS_KEYSIZE &&
53*a9643ea8Slogwang (key[i+4] & (1<<(7-b))))
54*a9643ea8Slogwang v |= 1;
55*a9643ea8Slogwang }
56*a9643ea8Slogwang }
57*a9643ea8Slogwang return (hash);
58*a9643ea8Slogwang }
59