1 /* 2 * Copyright (c) Ian F. Darwin 1986-1995. 3 * Software written by Ian F. Darwin and others; 4 * maintained 1995-present by Christos Zoulas and others. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice immediately at the beginning of the file, without modification, 11 * this list of conditions, and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 /* 29 * apprentice - make one pass through /etc/magic, learning its secrets. 30 */ 31 32 #include "file.h" 33 34 #ifndef lint 35 FILE_RCSID("@(#)$File: swap.c,v 1.1 2026/04/19 19:56:49 christos Exp $") 36 #endif /* lint */ 37 38 #include "swap.h" 39 40 #if !defined(HAVE_BYTESWAP_H) && !defined(HAVE_SYS_BSWAP_H) 41 /* 42 * swap a short 43 */ 44 file_protected uint16_t 45 file_swap2(uint16_t sv) 46 { 47 uint16_t rv; 48 uint8_t *s = RCAST(uint8_t *, RCAST(void *, &sv)); 49 uint8_t *d = RCAST(uint8_t *, RCAST(void *, &rv)); 50 d[0] = s[1]; 51 d[1] = s[0]; 52 return rv; 53 } 54 55 /* 56 * swap an int 57 */ 58 file_protected uint32_t 59 file_swap4(uint32_t sv) 60 { 61 uint32_t rv; 62 uint8_t *s = RCAST(uint8_t *, RCAST(void *, &sv)); 63 uint8_t *d = RCAST(uint8_t *, RCAST(void *, &rv)); 64 d[0] = s[3]; 65 d[1] = s[2]; 66 d[2] = s[1]; 67 d[3] = s[0]; 68 return rv; 69 } 70 71 /* 72 * swap a quad 73 */ 74 file_protected uint64_t 75 file_swap8(uint64_t sv) 76 { 77 uint64_t rv; 78 uint8_t *s = RCAST(uint8_t *, RCAST(void *, &sv)); 79 uint8_t *d = RCAST(uint8_t *, RCAST(void *, &rv)); 80 # if 0 81 d[0] = s[3]; 82 d[1] = s[2]; 83 d[2] = s[1]; 84 d[3] = s[0]; 85 d[4] = s[7]; 86 d[5] = s[6]; 87 d[6] = s[5]; 88 d[7] = s[4]; 89 # else 90 d[0] = s[7]; 91 d[1] = s[6]; 92 d[2] = s[5]; 93 d[3] = s[4]; 94 d[4] = s[3]; 95 d[5] = s[2]; 96 d[6] = s[1]; 97 d[7] = s[0]; 98 # endif 99 return rv; 100 } 101 #endif 102