xref: /illumos-gate/usr/src/lib/iconv_modules/common/common_utf8.c (revision 22028508fd28d36ff74dc02c5774a8ba1f0db045)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/types.h>
28 #include "../inc/common_defs.h"
29 
30 /*
31  * convert utf8 string to unicode
32  * return value: 0 - fail
33  *               1 - success
34  */
35 int
36 convert_utf8_to_ucs4(uchar_t *ib, int utf8_len, uint_t *unicode)
37 {
38    uchar_t first_byte = *ib;
39    uint_t u4;
40 
41    if ( number_of_bytes_in_utf8_char[first_byte] != utf8_len) return 0;
42 
43    u4 = (uint_t)(*ib++ & masks_tbl[utf8_len]);
44    for (; utf8_len > 1; utf8_len--)
45      {
46 	u4 = (u4 << ICV_UTF8_BIT_SHIFT) | (((uint_t) *ib) & ICV_UTF8_BIT_MASK);
47 	++ib;
48      }
49 
50    *unicode = u4;
51 
52    return 1;
53 }
54 
55 /*
56  * check whether the input 'str' is valid UTF-8 byte sequence or not,
57  * which lenght is specified by 'utf8_len'
58  *
59  * return: 0 - invalid byte sequence
60  * 	   1 - valid byte sequence
61  */
62 int
63 is_valid_utf8_string(uchar_t *str, int utf8_len)
64 {
65    uint_t unicode = 0;
66    uchar_t *ib = str;
67    uchar_t first_byte;
68    int is_second_byte = 0, len=utf8_len;
69 
70    if (number_of_bytes_in_utf8_char[*ib] == ICV_TYPE_ILLEGAL_CHAR ||
71        number_of_bytes_in_utf8_char[*ib] != utf8_len ) return 0;
72 
73    first_byte = *ib;
74    --utf8_len;
75    ++ib;
76    is_second_byte = 1;
77 
78    while (utf8_len != 0)
79      {
80 	if (is_second_byte)
81 	  {
82 	     if ( *ib < valid_min_2nd_byte[first_byte] || *ib > valid_max_2nd_byte[first_byte] )
83 	        return 0;
84 	     is_second_byte = 0;
85 	  }
86 	else if ((*ib & 0xc0) != 0x80) /* 0x80 -- 0xbf */
87 		return 0;
88 
89         --utf8_len;
90 	++ib;
91      }
92 
93    convert_utf8_to_ucs4(str, len, &unicode);
94    if (unicode == 0xFFFE || unicode == 0xFFFF) return 0;
95 
96    return 1;
97 }
98