1 /* $NetBSD: unicode.h,v 1.3 2005/12/11 12:24:25 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2001, 2004 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, 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 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the NetBSD 18 * Foundation, Inc. and its contributors. 19 * 4. Neither the name of The NetBSD Foundation nor the names of its 20 * contributors may be used to endorse or promote products derived 21 * from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /* 37 * Routines for handling Unicode encoded in UTF-8 form, code derived from 38 * src/lib/libc/locale/utf2.c. 39 */ 40 41 /* 42 * Read one UTF8-encoded character off the string, shift the string pointer 43 * and return the character. 44 */ 45 static u_int16_t 46 wget_utf8(const char **str, size_t *sz) 47 { 48 int c; 49 u_int16_t rune = 0; 50 const char *s = *str; 51 static const int _utf_count[16] = { 52 1, 1, 1, 1, 1, 1, 1, 1, 53 0, 0, 0, 0, 2, 2, 3, 0, 54 }; 55 56 /* must be called with at least one byte remaining */ 57 KASSERT(*sz > 0); 58 59 c = _utf_count[(s[0] & 0xf0) >> 4]; 60 if (c == 0 || c > *sz) { 61 decoding_error: 62 /* 63 * The first character is in range 128-255 and doesn't 64 * mark valid a valid UTF-8 sequence. There is not much 65 * we can do with this, so handle by returning 66 * the first character as if it would be a correctly 67 * encoded ISO-8859-1 character. 68 */ 69 c = 1; 70 } 71 72 switch (c) { 73 case 1: 74 rune = s[0] & 0xff; 75 break; 76 case 2: 77 if ((s[1] & 0xc0) != 0x80) 78 goto decoding_error; 79 rune = ((s[0] & 0x1F) << 6) | (s[1] & 0x3F); 80 break; 81 case 3: 82 if ((s[1] & 0xC0) != 0x80 || (s[2] & 0xC0) != 0x80) 83 goto decoding_error; 84 rune = ((s[0] & 0x1F) << 12) | ((s[1] & 0x3F) << 6) 85 | (s[2] & 0x3F); 86 break; 87 } 88 89 *str += c; 90 *sz -= c; 91 return rune; 92 } 93 94 /* 95 * Encode wide character and write it to the string. 'n' specifies 96 * how much buffer space remains in 's'. Returns number of bytes written 97 * to the target string 's'. 98 */ 99 static int 100 wput_utf8(char *s, size_t n, u_int16_t wc) 101 { 102 if (wc & 0xf800) { 103 if (n < 3) { 104 /* bound check failure */ 105 return 0; 106 } 107 108 s[0] = 0xE0 | ((wc >> 12) & 0x0F); 109 s[1] = 0x80 | ((wc >> 6) & 0x3F); 110 s[2] = 0x80 | ((wc) & 0x3F); 111 return 3; 112 } else if (wc & 0x0780) { 113 if (n < 2) { 114 /* bound check failure */ 115 return 0; 116 } 117 118 s[0] = 0xC0 | ((wc >> 6) & 0x1F); 119 s[1] = 0x80 | ((wc) & 0x3F); 120 return 2; 121 } else { 122 if (n < 1) { 123 /* bound check failure */ 124 return 0; 125 } 126 127 s[0] = wc; 128 return 1; 129 } 130 } 131