1 /*
2  * Summary: interface for the encoding conversion functions
3  * Description: interface for the encoding conversion functions needed for
4  *              XML basic encoding and iconv() support.
5  *
6  * Related specs are
7  * rfc2044        (UTF-8 and UTF-16) F. Yergeau Alis Technologies
8  * [ISO-10646]    UTF-8 and UTF-16 in Annexes
9  * [ISO-8859-1]   ISO Latin-1 characters codes.
10  * [UNICODE]      The Unicode Consortium, "The Unicode Standard --
11  *                Worldwide Character Encoding -- Version 1.0", Addison-
12  *                Wesley, Volume 1, 1991, Volume 2, 1992.  UTF-8 is
13  *                described in Unicode Technical Report #4.
14  * [US-ASCII]     Coded Character Set--7-bit American Standard Code for
15  *                Information Interchange, ANSI X3.4-1986.
16  *
17  * Copy: See Copyright for the status of this software.
18  *
19  * Author: Daniel Veillard
20  */
21 
22 #ifndef __XML_CHAR_ENCODING_H__
23 #define __XML_CHAR_ENCODING_H__
24 
25 #include <libxml/xmlversion.h>
26 
27 #ifdef LIBXML_ICONV_ENABLED
28 #include <iconv.h>
29 #endif
30 #ifdef LIBXML_ICU_ENABLED
31 #include <unicode/ucnv.h>
32 #endif
33 #ifdef __cplusplus
34 extern "C" {
35 #endif
36 
37 /*
38  * xmlCharEncoding:
39  *
40  * Predefined values for some standard encodings.
41  * Libxml does not do beforehand translation on UTF8 and ISOLatinX.
42  * It also supports ASCII, ISO-8859-1, and UTF16 (LE and BE) by default.
43  *
44  * Anything else would have to be translated to UTF8 before being
45  * given to the parser itself. The BOM for UTF16 and the encoding
46  * declaration are looked at and a converter is looked for at that
47  * point. If not found the parser stops here as asked by the XML REC. A
48  * converter can be registered by the user using xmlRegisterCharEncodingHandler
49  * but the current form doesn't allow stateful transcoding (a serious
50  * problem agreed !). If iconv has been found it will be used
51  * automatically and allow stateful transcoding, the simplest is then
52  * to be sure to enable iconv and to provide iconv libs for the encoding
53  * support needed.
54  *
55  * Note that the generic "UTF-16" is not a predefined value.  Instead, only
56  * the specific UTF-16LE and UTF-16BE are present.
57  */
58 typedef enum {
59     XML_CHAR_ENCODING_ERROR=   -1, /* No char encoding detected */
60     XML_CHAR_ENCODING_NONE=	0, /* No char encoding detected */
61     XML_CHAR_ENCODING_UTF8=	1, /* UTF-8 */
62     XML_CHAR_ENCODING_UTF16LE=	2, /* UTF-16 little endian */
63     XML_CHAR_ENCODING_UTF16BE=	3, /* UTF-16 big endian */
64     XML_CHAR_ENCODING_UCS4LE=	4, /* UCS-4 little endian */
65     XML_CHAR_ENCODING_UCS4BE=	5, /* UCS-4 big endian */
66     XML_CHAR_ENCODING_EBCDIC=	6, /* EBCDIC uh! */
67     XML_CHAR_ENCODING_UCS4_2143=7, /* UCS-4 unusual ordering */
68     XML_CHAR_ENCODING_UCS4_3412=8, /* UCS-4 unusual ordering */
69     XML_CHAR_ENCODING_UCS2=	9, /* UCS-2 */
70     XML_CHAR_ENCODING_8859_1=	10,/* ISO-8859-1 ISO Latin 1 */
71     XML_CHAR_ENCODING_8859_2=	11,/* ISO-8859-2 ISO Latin 2 */
72     XML_CHAR_ENCODING_8859_3=	12,/* ISO-8859-3 */
73     XML_CHAR_ENCODING_8859_4=	13,/* ISO-8859-4 */
74     XML_CHAR_ENCODING_8859_5=	14,/* ISO-8859-5 */
75     XML_CHAR_ENCODING_8859_6=	15,/* ISO-8859-6 */
76     XML_CHAR_ENCODING_8859_7=	16,/* ISO-8859-7 */
77     XML_CHAR_ENCODING_8859_8=	17,/* ISO-8859-8 */
78     XML_CHAR_ENCODING_8859_9=	18,/* ISO-8859-9 */
79     XML_CHAR_ENCODING_2022_JP=  19,/* ISO-2022-JP */
80     XML_CHAR_ENCODING_SHIFT_JIS=20,/* Shift_JIS */
81     XML_CHAR_ENCODING_EUC_JP=   21,/* EUC-JP */
82     XML_CHAR_ENCODING_ASCII=    22 /* pure ASCII */
83 } xmlCharEncoding;
84 
85 /**
86  * xmlCharEncodingInputFunc:
87  * @out:  a pointer to an array of bytes to store the UTF-8 result
88  * @outlen:  the length of @out
89  * @in:  a pointer to an array of chars in the original encoding
90  * @inlen:  the length of @in
91  *
92  * Take a block of chars in the original encoding and try to convert
93  * it to an UTF-8 block of chars out.
94  *
95  * Returns the number of bytes written, -1 if lack of space, or -2
96  *     if the transcoding failed.
97  * The value of @inlen after return is the number of octets consumed
98  *     if the return value is positive, else unpredictiable.
99  * The value of @outlen after return is the number of octets consumed.
100  */
101 typedef int (* xmlCharEncodingInputFunc)(unsigned char *out, int *outlen,
102                                          const unsigned char *in, int *inlen);
103 
104 
105 /**
106  * xmlCharEncodingOutputFunc:
107  * @out:  a pointer to an array of bytes to store the result
108  * @outlen:  the length of @out
109  * @in:  a pointer to an array of UTF-8 chars
110  * @inlen:  the length of @in
111  *
112  * Take a block of UTF-8 chars in and try to convert it to another
113  * encoding.
114  * Note: a first call designed to produce heading info is called with
115  * in = NULL. If stateful this should also initialize the encoder state.
116  *
117  * Returns the number of bytes written, -1 if lack of space, or -2
118  *     if the transcoding failed.
119  * The value of @inlen after return is the number of octets consumed
120  *     if the return value is positive, else unpredictiable.
121  * The value of @outlen after return is the number of octets produced.
122  */
123 typedef int (* xmlCharEncodingOutputFunc)(unsigned char *out, int *outlen,
124                                           const unsigned char *in, int *inlen);
125 
126 
127 /*
128  * Block defining the handlers for non UTF-8 encodings.
129  * If iconv is supported, there are two extra fields.
130  */
131 #ifdef LIBXML_ICU_ENABLED
132 struct _uconv_t {
133   UConverter *uconv; /* for conversion between an encoding and UTF-16 */
134   UConverter *utf8; /* for conversion between UTF-8 and UTF-16 */
135 };
136 typedef struct _uconv_t uconv_t;
137 #endif
138 
139 typedef struct _xmlCharEncodingHandler xmlCharEncodingHandler;
140 typedef xmlCharEncodingHandler *xmlCharEncodingHandlerPtr;
141 struct _xmlCharEncodingHandler {
142     char                       *name;
143     xmlCharEncodingInputFunc   input;
144     xmlCharEncodingOutputFunc  output;
145 #ifdef LIBXML_ICONV_ENABLED
146     iconv_t                    iconv_in;
147     iconv_t                    iconv_out;
148 #endif /* LIBXML_ICONV_ENABLED */
149 #ifdef LIBXML_ICU_ENABLED
150     uconv_t                    *uconv_in;
151     uconv_t                    *uconv_out;
152 #endif /* LIBXML_ICU_ENABLED */
153 };
154 
155 #ifdef __cplusplus
156 }
157 #endif
158 #include <libxml/tree.h>
159 #ifdef __cplusplus
160 extern "C" {
161 #endif
162 
163 /*
164  * Interfaces for encoding handlers.
165  */
166 XMLPUBFUN void XMLCALL
167 	xmlInitCharEncodingHandlers	(void);
168 XMLPUBFUN void XMLCALL
169 	xmlCleanupCharEncodingHandlers	(void);
170 XMLPUBFUN void XMLCALL
171 	xmlRegisterCharEncodingHandler	(xmlCharEncodingHandlerPtr handler);
172 XMLPUBFUN xmlCharEncodingHandlerPtr XMLCALL
173 	xmlGetCharEncodingHandler	(xmlCharEncoding enc);
174 XMLPUBFUN xmlCharEncodingHandlerPtr XMLCALL
175 	xmlFindCharEncodingHandler	(const char *name);
176 XMLPUBFUN xmlCharEncodingHandlerPtr XMLCALL
177 	xmlNewCharEncodingHandler	(const char *name,
178 					 xmlCharEncodingInputFunc input,
179 					 xmlCharEncodingOutputFunc output);
180 
181 /*
182  * Interfaces for encoding names and aliases.
183  */
184 XMLPUBFUN int XMLCALL
185 	xmlAddEncodingAlias		(const char *name,
186 					 const char *alias);
187 XMLPUBFUN int XMLCALL
188 	xmlDelEncodingAlias		(const char *alias);
189 XMLPUBFUN const char * XMLCALL
190 	xmlGetEncodingAlias		(const char *alias);
191 XMLPUBFUN void XMLCALL
192 	xmlCleanupEncodingAliases	(void);
193 XMLPUBFUN xmlCharEncoding XMLCALL
194 	xmlParseCharEncoding		(const char *name);
195 XMLPUBFUN const char * XMLCALL
196 	xmlGetCharEncodingName		(xmlCharEncoding enc);
197 
198 /*
199  * Interfaces directly used by the parsers.
200  */
201 XMLPUBFUN xmlCharEncoding XMLCALL
202 	xmlDetectCharEncoding		(const unsigned char *in,
203 					 int len);
204 
205 XMLPUBFUN int XMLCALL
206 	xmlCharEncOutFunc		(xmlCharEncodingHandler *handler,
207 					 xmlBufferPtr out,
208 					 xmlBufferPtr in);
209 
210 XMLPUBFUN int XMLCALL
211 	xmlCharEncInFunc		(xmlCharEncodingHandler *handler,
212 					 xmlBufferPtr out,
213 					 xmlBufferPtr in);
214 XMLPUBFUN int XMLCALL
215 	xmlCharEncFirstLine		(xmlCharEncodingHandler *handler,
216 					 xmlBufferPtr out,
217 					 xmlBufferPtr in);
218 XMLPUBFUN int XMLCALL
219 	xmlCharEncCloseFunc		(xmlCharEncodingHandler *handler);
220 
221 /*
222  * Export a few useful functions
223  */
224 #ifdef LIBXML_OUTPUT_ENABLED
225 XMLPUBFUN int XMLCALL
226 	UTF8Toisolat1			(unsigned char *out,
227 					 int *outlen,
228 					 const unsigned char *in,
229 					 int *inlen);
230 #endif /* LIBXML_OUTPUT_ENABLED */
231 XMLPUBFUN int XMLCALL
232 	isolat1ToUTF8			(unsigned char *out,
233 					 int *outlen,
234 					 const unsigned char *in,
235 					 int *inlen);
236 #ifdef __cplusplus
237 }
238 #endif
239 
240 #endif /* __XML_CHAR_ENCODING_H__ */
241