1 /*- 2 * Copyright (c) 1982, 1989, 1993 3 * The Regents of the University of California. 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 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)if_ethersubr.c 8.1 (Berkeley) 6/10/93 30 * $FreeBSD: src/sys/net/if_ethersubr.c,v 1.193.2.12 2006/08/28 02:54:14 thompsa Exp $ 31 */ 32 #include <stdio.h> 33 #include <sys/types.h> 34 #include <net/ethernet.h> 35 36 #if 0 37 /* 38 * This is for reference. We have a table-driven version 39 * of the little-endian crc32 generator, which is faster 40 * than the double-loop. 41 */ 42 uint32_t 43 ether_crc32_le(const uint8_t *buf, size_t len) 44 { 45 size_t i; 46 uint32_t crc; 47 int bit; 48 uint8_t data; 49 50 crc = 0xffffffff; /* initial value */ 51 52 for (i = 0; i < len; i++) { 53 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) 54 carry = (crc ^ data) & 1; 55 crc >>= 1; 56 if (carry) 57 crc = (crc ^ ETHER_CRC_POLY_LE); 58 } 59 60 return (crc); 61 } 62 #else 63 uint32_t 64 ether_crc32_le(const uint8_t *buf, size_t len) 65 { 66 static const uint32_t crctab[] = { 67 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 68 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, 69 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, 70 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c 71 }; 72 size_t i; 73 uint32_t crc; 74 75 crc = 0xffffffff; /* initial value */ 76 77 for (i = 0; i < len; i++) { 78 crc ^= buf[i]; 79 crc = (crc >> 4) ^ crctab[crc & 0xf]; 80 crc = (crc >> 4) ^ crctab[crc & 0xf]; 81 } 82 83 return (crc); 84 } 85 #endif 86 87 uint32_t 88 ether_crc32_be(const uint8_t *buf, size_t len) 89 { 90 size_t i; 91 uint32_t crc, carry; 92 int bit; 93 uint8_t data; 94 95 crc = 0xffffffff; /* initial value */ 96 97 for (i = 0; i < len; i++) { 98 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) { 99 carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01); 100 crc <<= 1; 101 if (carry) 102 crc = (crc ^ ETHER_CRC_POLY_BE) | carry; 103 } 104 } 105 106 return (crc); 107 } 108 109 char * 110 ether_sprintf(const u_char *ap) 111 { 112 static char etherbuf[18]; 113 snprintf(etherbuf, sizeof (etherbuf), 114 "%02x:%02x:%02x:%02x:%02x:%02x", 115 (unsigned)ap[0], (unsigned)ap[1], (unsigned)ap[2], 116 (unsigned)ap[3], (unsigned)ap[4], (unsigned)ap[5]); 117 return (etherbuf); 118 } 119