1 /*
2 * Copyright (c) 2003-2004, Artem B. Bityuckiy
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25 #define _DEFAULT_SOURCE
26 #include <_ansi.h>
27 #include <newlib.h>
28 #include <sys/types.h>
29 #include <string.h>
30 #include <stdlib.h>
31 #include <errno.h>
32 #include <ctype.h>
33 #include <sys/iconvnls.h>
34 #include "local.h"
35
36 /*
37 * canonical_form - canonize 'str'.
38 *
39 * PARAMETERS:
40 * const char *str - string to canonize.
41 *
42 * DESCRIPTION:
43 * Converts all letters to small and substitute all '-' characters by '_'
44 * characters.
45 *
46 * RETURN:
47 * Returns canonical form of 'str' if success, NULL if failure.
48 */
49 static const char *
canonical_form(const char * str)50 canonical_form (
51 const char *str)
52 {
53 char *p, *p1;
54
55 if (str == NULL || (p = p1 = strdup (str)) == NULL)
56 return (const char *)NULL;
57
58 for (; *str; str++, p++)
59 {
60 if (*str == '-')
61 *p = '_';
62 else
63 *p = tolower (*str);
64 }
65
66 return (const char *)p1;
67 }
68
69 /*
70 * find_alias - find encoding name name by it's alias.
71 *
72 * PARAMETERS:
73 * const char *alias - alias by which "official" name should be found.
74 * const char *table - aliases table.
75 * int len - aliases table length.
76 *
77 * DESCRIPTION:
78 * 'table' contains the list of encoding names and aliases.
79 * Names go first, e.g.:
80 *
81 * name1 alias11 alias12 alias1N
82 * name2 alias21 alias22 alias2N
83 * nameM aliasM1 aliasM2 aliasMN
84 *
85 * If line begins with backspace it is considered as the continuation of
86 * previous line.
87 *
88 * RETURN:
89 * Returns pointer to name found if success. In case of error returns NULL
90 * and sets current thread's/process's errno.
91 */
92 static char *
find_alias(const char * alias,const char * table,int len)93 find_alias (
94 const char *alias,
95 const char *table,
96 int len)
97 {
98 const char *end;
99 const char *p;
100 int l;
101 const char *ptable = table;
102 const char *table_end = table + len;
103
104 if (table == NULL || alias == NULL || *table == '\0' || *alias == '\0')
105 return NULL;
106
107 l = strlen (alias);
108 search_again:
109 if (len < l || (p = strnstr (ptable, alias, len)) == NULL)
110 return NULL;
111
112 /* Check that substring is segregated by '\n', '\t' or ' ' */
113 if (!((p == table || isspace (*(p-1)) || *(p-1) == '\n')
114 && (p+l == table_end || isspace (*(p+l)) || *(p+l) == '\n')))
115 {
116 ptable = p + l;
117 len = table_end - ptable;
118 goto search_again;
119 }
120
121 while(--p > table && *p != '\n');
122
123 if (*(++p) == '#')
124 return NULL;
125
126 for (end = p + 1; !isspace (*end) && *end != '\n' && *end != '\0'; end++);
127
128 return strndup (p, (size_t)(end - p));
129 }
130
131 /*
132 * _iconv_resolve_encoding_name - resolves encoding's name by given alias.
133 *
134 * PARAMETERS:
135 * const char *ca - encoding alias to resolve.
136 *
137 * DESCRIPTION:
138 * First, tries to find 'ca' among built-in aliases. If not found, tries to
139 * find it external file.
140 *
141 * RETURN:
142 * Encoding name if found. In case of error returns NULL
143 * and sets current thread's/process's errno.
144 */
145 char *
_iconv_resolve_encoding_name(const char * ca)146 _iconv_resolve_encoding_name (
147 const char *ca)
148 {
149 char *p = (char *)ca;
150
151 /* Alias shouldn't contain white spaces, '\n' and '\r' symbols */
152 while (*p)
153 if (*p == ' ' || *p == '\r' || *p++ == '\n')
154 return NULL;
155
156 if ((ca = canonical_form (ca)) == NULL)
157 return NULL;
158
159 p = find_alias (ca, _iconv_aliases, strlen (_iconv_aliases));
160
161 free ((void *)ca);
162 return p;
163 }
164
165
