1 /* Conversion from and to IBM933.
2    Copyright (C) 2000-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 /* IBM933 is designed for the representation of Korean using a stateful
20    EBCDIC encoding scheme.  It is also known as CCSID 933 or CP933. See:
21    https://www-01.ibm.com/software/globalization/ccsid/ccsid933.html */
22 
23 #include <dlfcn.h>
24 #include <stdint.h>
25 #include <wchar.h>
26 #include <byteswap.h>
27 #include "ibm933.h"
28 
29 /* The shift sequences for this charset (it does not use ESC).  */
30 #define SI 		0x0F  /* Shift In, host code to turn DBCS off.  */
31 #define SO 		0x0E  /* Shift Out, host code to turn DBCS on.  */
32 
33 /* Definitions used in the body of the `gconv' function.  */
34 #define CHARSET_NAME	"IBM933//"
35 #define FROM_LOOP	from_ibm933
36 #define TO_LOOP		to_ibm933
37 #define ONE_DIRECTION			0
38 #define FROM_LOOP_MIN_NEEDED_FROM	1
39 #define FROM_LOOP_MAX_NEEDED_FROM	2
40 #define FROM_LOOP_MIN_NEEDED_TO		4
41 #define FROM_LOOP_MAX_NEEDED_TO		4
42 #define TO_LOOP_MIN_NEEDED_FROM		4
43 #define TO_LOOP_MAX_NEEDED_FROM		4
44 #define TO_LOOP_MIN_NEEDED_TO		1
45 #define TO_LOOP_MAX_NEEDED_TO		3
46 #define PREPARE_LOOP \
47   int save_curcs;							      \
48   int *curcsp = &data->__statep->__count;
49 #define EXTRA_LOOP_ARGS		, curcsp
50 
51 /* Definitions of initialization and destructor function.  */
52 #define DEFINE_INIT	1
53 #define DEFINE_FINI	1
54 
55 
56 /* Since this is a stateful encoding we have to provide code which resets
57    the output state to the initial state.  This has to be done during the
58    flushing.  */
59 #define EMIT_SHIFT_TO_INIT \
60   if ((data->__statep->__count & ~7) != sb)				      \
61     {									      \
62       if (FROM_DIRECTION)						      \
63 	data->__statep->__count &= 7;					      \
64       else								      \
65 	{								      \
66 	  /* We are not in the initial state.  To switch back we have	      \
67 	     to emit `SI'.  */						      \
68 	  if (__glibc_unlikely (outbuf >= outend))			      \
69 	    /* We don't have enough room in the output buffer.  */	      \
70 	    status = __GCONV_FULL_OUTPUT;				      \
71 	  else								      \
72 	    {								      \
73 	      /* Write out the shift sequence.  */			      \
74 	      *outbuf++ = SI;						      \
75 	      data->__statep->__count &= 7;				      \
76 	    }								      \
77 	}								      \
78     }
79 
80 
81 /* Since we might have to reset input pointer we must be able to save
82    and retore the state.  */
83 #define SAVE_RESET_STATE(Save) \
84   if (Save)								      \
85     save_curcs = *curcsp;						      \
86   else									      \
87     *curcsp = save_curcs
88 
89 
90 /* Current codeset type.  */
91 enum
92 {
93   sb = 0,
94   db = 64
95 };
96 
97 /* First, define the conversion function from IBM-933 to UCS4.  */
98 #define MIN_NEEDED_INPUT	FROM_LOOP_MIN_NEEDED_FROM
99 #define MAX_NEEDED_INPUT	FROM_LOOP_MAX_NEEDED_FROM
100 #define MIN_NEEDED_OUTPUT	FROM_LOOP_MIN_NEEDED_TO
101 #define MAX_NEEDED_OUTPUT	FROM_LOOP_MAX_NEEDED_TO
102 #define LOOPFCT 		FROM_LOOP
103 #define BODY \
104   {									      \
105     uint32_t ch = *inptr;						      \
106     uint32_t res;							      \
107 									      \
108     if (__builtin_expect (ch, 0) == SO)					      \
109       {									      \
110 	/* Shift OUT, change to DBCS converter (redundant escape okay).  */   \
111 	curcs = db;							      \
112 	++inptr;							      \
113 	continue;							      \
114       }									      \
115     else if (__builtin_expect (ch, 0) == SI)				      \
116       {									      \
117 	/* Shift IN, change to SBCS converter (redundant escape okay).  */    \
118 	curcs = sb;							      \
119 	++inptr;							      \
120 	continue;							      \
121       }									      \
122 									      \
123     if (curcs == sb)							      \
124       {									      \
125 	/* Use the IBM933 table for single byte.  */			      \
126 	res = __ibm933sb_to_ucs4[ch];					      \
127 	if (__builtin_expect (res, L'\1') == L'\0' && ch != '\0')	      \
128 	  {								      \
129 	    /* This is an illegal character.  */			      \
130 	    STANDARD_FROM_LOOP_ERR_HANDLER (1);				      \
131 	  }								      \
132 	else								      \
133 	  {								      \
134 	    put32 (outptr, res);					      \
135 	    outptr += 4;						      \
136 	  }								      \
137 	++inptr;							      \
138       }									      \
139     else								      \
140       {									      \
141 	const struct gap *rp2 = __ibm933db_to_ucs4_idx;			      \
142 									      \
143 	assert (curcs == db);						      \
144 									      \
145 	/* Use the IBM933 table for double byte.  */			      \
146 	if (__glibc_unlikely (inptr + 1 >= inend))			      \
147 	  {								      \
148 	    /* The second character is not available.  Store the	      \
149 	       intermediate result. */					      \
150 	    result = __GCONV_INCOMPLETE_INPUT;				      \
151 	    break;							      \
152 	  }								      \
153 									      \
154 	ch = (ch * 0x100) + inptr[1];					      \
155 	while (ch > rp2->end)						      \
156 	  ++rp2;							      \
157 									      \
158 	if (__builtin_expect (rp2->start == 0xffff, 0)			      \
159 	    || __builtin_expect (ch < rp2->start, 0)			      \
160 	    || (res = __ibm933db_to_ucs4[ch + rp2->idx],		      \
161 		__builtin_expect (res, L'\1') == L'\0' && ch != '\0'))	      \
162 	  {								      \
163 	    /* This is an illegal character.  */			      \
164 	    STANDARD_FROM_LOOP_ERR_HANDLER (2);				      \
165 	  }								      \
166 	else								      \
167 	  {								      \
168 	    put32 (outptr, res);					      \
169 	    outptr += 4;						      \
170 	    inptr += 2;							      \
171 	  }								      \
172       }									      \
173   }
174 #define LOOP_NEED_FLAGS
175 #define EXTRA_LOOP_DECLS	, int *curcsp
176 #define INIT_PARAMS		int curcs = *curcsp & ~7
177 #define UPDATE_PARAMS		*curcsp = curcs
178 #include <iconv/loop.c>
179 
180 /* Next, define the other direction.  */
181 #define MIN_NEEDED_INPUT	TO_LOOP_MIN_NEEDED_FROM
182 #define MAX_NEEDED_INPUT	TO_LOOP_MAX_NEEDED_FROM
183 #define MIN_NEEDED_OUTPUT	TO_LOOP_MIN_NEEDED_TO
184 #define MAX_NEEDED_OUTPUT	TO_LOOP_MAX_NEEDED_TO
185 #define LOOPFCT			TO_LOOP
186 #define BODY \
187   {									      \
188     uint32_t ch = get32 (inptr);					      \
189     const struct gap *rp1 = __ucs4_to_ibm933sb_idx;			      \
190     const struct gap *rp2 = __ucs4_to_ibm933db_idx;			      \
191 									      \
192     if (__glibc_unlikely (ch >= 0xffff))				      \
193       {									      \
194 	UNICODE_TAG_HANDLER (ch, 4);					      \
195 									      \
196 	STANDARD_TO_LOOP_ERR_HANDLER (4);				      \
197       }									      \
198 									      \
199     while (ch > rp1->end)						      \
200       ++rp1;								      \
201 									      \
202     /* Use the UCS4 table for single byte.  */				      \
203     unsigned char sbconv;						      \
204     if (__builtin_expect (ch < rp1->start, 0)				      \
205 	|| (sbconv = __ucs4_to_ibm933sb[ch + rp1->idx],			      \
206 	    __builtin_expect (sbconv, L'\1') == L'\0' && ch != '\0'))	      \
207       {									      \
208 	/* Use the UCS4 table for double byte.  */			      \
209 	while (ch > rp2->end)						      \
210 	  ++rp2;							      \
211 									      \
212 	const char *cp;							      \
213 	if (__builtin_expect (ch < rp2->start, 0)			      \
214 	    || (cp = __ucs4_to_ibm933db[ch + rp2->idx],			      \
215 		__builtin_expect (cp[0], L'\1')==L'\0' && ch != '\0'))	      \
216 	  {								      \
217 	    /* This is an illegal character.  */			      \
218 	    STANDARD_TO_LOOP_ERR_HANDLER (4);				      \
219 	  }								      \
220 	else								      \
221 	  {								      \
222 	    if (curcs == sb)						      \
223 	      {								      \
224 		if (__glibc_unlikely (outptr + 1 > outend))		      \
225 		  {							      \
226 		    result = __GCONV_FULL_OUTPUT;			      \
227 		    break;						      \
228 		  }							      \
229 		*outptr++ = SO;						      \
230 		curcs = db;						      \
231 	      }								      \
232 									      \
233 	    if (__glibc_unlikely (outptr + 2 > outend))			      \
234 	      {								      \
235 		result = __GCONV_FULL_OUTPUT;				      \
236 		break;							      \
237 	      }								      \
238 	    *outptr++ = cp[0];						      \
239 	    *outptr++ = cp[1];						      \
240 	  }								      \
241       }									      \
242     else								      \
243       {									      \
244 	if (curcs == db)						      \
245 	  {								      \
246 	    if (__glibc_unlikely (outptr + 1 > outend))			      \
247 	      {								      \
248 		result = __GCONV_FULL_OUTPUT;				      \
249 		break;							      \
250 	      }								      \
251 	    *outptr++ = SI;						      \
252 	    curcs = sb;							      \
253 	  }								      \
254 									      \
255 	if (__glibc_unlikely (outptr + 1 > outend))			      \
256 	  {								      \
257 	    result = __GCONV_FULL_OUTPUT;				      \
258 	    break;							      \
259 	  }								      \
260 	*outptr++ = sbconv;						      \
261       }									      \
262 									      \
263     /* Now that we wrote the output increment the input pointer.  */	      \
264     inptr += 4;								      \
265   }
266 #define LOOP_NEED_FLAGS
267 #define EXTRA_LOOP_DECLS	, int *curcsp
268 #define INIT_PARAMS		int curcs = *curcsp & ~7
269 #define REINIT_PARAMS		curcs = *curcsp & ~7
270 #define UPDATE_PARAMS		*curcsp = curcs
271 #include <iconv/loop.c>
272 
273 /* Now define the toplevel functions.  */
274 #include <iconv/skeleton.c>
275