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 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