1/****************************************************************************
2 *
3 * gxvmort.c
4 *
5 * TrueTypeGX/AAT mort table validation (body).
6 *
7 * Copyright (C) 2005-2023 by
8 * suzuki toshiya, Masatake YAMATO, Red Hat K.K.,
9 * David Turner, Robert Wilhelm, and Werner Lemberg.
10 *
11 * This file is part of the FreeType project, and may only be used,
12 * modified, and distributed under the terms of the FreeType project
13 * license, LICENSE.TXT. By continuing to use, modify, or distribute
14 * this file you indicate that you have read the license and
15 * understand and accept it fully.
16 *
17 */
18
19/****************************************************************************
20 *
21 * gxvalid is derived from both gxlayout module and otvalid module.
22 * Development of gxlayout is supported by the Information-technology
23 * Promotion Agency(IPA), Japan.
24 *
25 */
26
27
28#include "gxvmort.h"
29#include "gxvfeat.h"
30
31
32 /**************************************************************************
33 *
34 * The macro FT_COMPONENT is used in trace mode. It is an implicit
35 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
36 * messages during execution.
37 */
38#undef FT_COMPONENT
39#define FT_COMPONENT gxvmort
40
41
42 static void
43 gxv_mort_feature_validate( GXV_mort_feature f,
44 GXV_Validator gxvalid )
45 {
46 if ( f->featureType >= gxv_feat_registry_length )
47 {
48 GXV_TRACE(( "featureType %d is out of registered range, "
49 "setting %d is unchecked\n",
50 f->featureType, f->featureSetting ));
51 GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
52 }
53 else if ( !gxv_feat_registry[f->featureType].existence )
54 {
55 GXV_TRACE(( "featureType %d is within registered area "
56 "but undefined, setting %d is unchecked\n",
57 f->featureType, f->featureSetting ));
58 GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
59 }
60 else
61 {
62 FT_Byte nSettings_max;
63
64
65 /* nSettings in gxvfeat.c is halved for exclusive on/off settings */
66 nSettings_max = gxv_feat_registry[f->featureType].nSettings;
67 if ( gxv_feat_registry[f->featureType].exclusive )
68 nSettings_max = (FT_Byte)( 2 * nSettings_max );
69
70 GXV_TRACE(( "featureType %d is registered", f->featureType ));
71 GXV_TRACE(( "setting %d", f->featureSetting ));
72
73 if ( f->featureSetting > nSettings_max )
74 {
75 GXV_TRACE(( "out of defined range %d", nSettings_max ));
76 GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
77 }
78 GXV_TRACE(( "\n" ));
79 }
80
81 /* TODO: enableFlags must be unique value in specified chain? */
82 }
83
84
85 /*
86 * nFeatureFlags is typed to FT_ULong to accept that in
87 * mort (typed FT_UShort) and morx (typed FT_ULong).
88 */
89 FT_LOCAL_DEF( void )
90 gxv_mort_featurearray_validate( FT_Bytes table,
91 FT_Bytes limit,
92 FT_ULong nFeatureFlags,
93 GXV_Validator gxvalid )
94 {
95 FT_Bytes p = table;
96 FT_ULong i;
97
98 GXV_mort_featureRec f = GXV_MORT_FEATURE_OFF;
99
100
101 GXV_NAME_ENTER( "mort feature list" );
102 for ( i = 0; i < nFeatureFlags; i++ )
103 {
104 GXV_LIMIT_CHECK( 2 + 2 + 4 + 4 );
105 f.featureType = FT_NEXT_USHORT( p );
106 f.featureSetting = FT_NEXT_USHORT( p );
107 f.enableFlags = FT_NEXT_ULONG( p );
108 f.disableFlags = FT_NEXT_ULONG( p );
109
110 gxv_mort_feature_validate( &f, gxvalid );
111 }
112
113 if ( !IS_GXV_MORT_FEATURE_OFF( f ) )
114 FT_INVALID_DATA;
115
116 gxvalid->subtable_length = (FT_ULong)( p - table );
117 GXV_EXIT;
118 }
119
120
121 FT_LOCAL_DEF( void )
122 gxv_mort_coverage_validate( FT_UShort coverage,
123 GXV_Validator gxvalid )
124 {
125 FT_UNUSED( gxvalid );
126 FT_UNUSED( coverage );
127
128#ifdef FT_DEBUG_LEVEL_TRACE
129 if ( coverage & 0x8000U )
130 GXV_TRACE(( " this subtable is for vertical text only\n" ));
131 else
132 GXV_TRACE(( " this subtable is for horizontal text only\n" ));
133
134 if ( coverage & 0x4000 )
135 GXV_TRACE(( " this subtable is applied to glyph array "
136 "in descending order\n" ));
137 else
138 GXV_TRACE(( " this subtable is applied to glyph array "
139 "in ascending order\n" ));
140
141 if ( coverage & 0x2000 )
142 GXV_TRACE(( " this subtable is forcibly applied to "
143 "vertical/horizontal text\n" ));
144
145 if ( coverage & 0x1FF8 )
146 GXV_TRACE(( " coverage has non-zero bits in reserved area\n" ));
147#endif
148 }
149
150
151 static void
152 gxv_mort_subtables_validate( FT_Bytes table,
153 FT_Bytes limit,
154 FT_UShort nSubtables,
155 GXV_Validator gxvalid )
156 {
157 FT_Bytes p = table;
158
159 GXV_Validate_Func fmt_funcs_table[] =
160 {
161 gxv_mort_subtable_type0_validate, /* 0 */
162 gxv_mort_subtable_type1_validate, /* 1 */
163 gxv_mort_subtable_type2_validate, /* 2 */
164 NULL, /* 3 */
165 gxv_mort_subtable_type4_validate, /* 4 */
166 gxv_mort_subtable_type5_validate, /* 5 */
167
168 };
169
170 FT_UShort i;
171
172
173 GXV_NAME_ENTER( "subtables in a chain" );
174
175 for ( i = 0; i < nSubtables; i++ )
176 {
177 GXV_Validate_Func func;
178
179 FT_UShort length;
180 FT_UShort coverage;
181#ifdef GXV_LOAD_UNUSED_VARS
182 FT_ULong subFeatureFlags;
183#endif
184 FT_UInt type;
185 FT_UInt rest;
186
187
188 GXV_LIMIT_CHECK( 2 + 2 + 4 );
189 length = FT_NEXT_USHORT( p );
190 coverage = FT_NEXT_USHORT( p );
191#ifdef GXV_LOAD_UNUSED_VARS
192 subFeatureFlags = FT_NEXT_ULONG( p );
193#else
194 p += 4;
195#endif
196
197 GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n",
198 i + 1, nSubtables, length ));
199 type = coverage & 0x0007;
200 rest = length - ( 2 + 2 + 4 );
201
202 GXV_LIMIT_CHECK( rest );
203 gxv_mort_coverage_validate( coverage, gxvalid );
204
205 if ( type > 5 )
206 FT_INVALID_FORMAT;
207
208 func = fmt_funcs_table[type];
209 if ( !func )
210 GXV_TRACE(( "morx type %d is reserved\n", type ));
211
212 func( p, p + rest, gxvalid );
213
214 p += rest;
215 /* TODO: validate subFeatureFlags */
216 }
217
218 gxvalid->subtable_length = (FT_ULong)( p - table );
219
220 GXV_EXIT;
221 }
222
223
224 static void
225 gxv_mort_chain_validate( FT_Bytes table,
226 FT_Bytes limit,
227 GXV_Validator gxvalid )
228 {
229 FT_Bytes p = table;
230#ifdef GXV_LOAD_UNUSED_VARS
231 FT_ULong defaultFlags;
232#endif
233 FT_ULong chainLength;
234 FT_UShort nFeatureFlags;
235 FT_UShort nSubtables;
236
237
238 GXV_NAME_ENTER( "mort chain header" );
239
240 GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 );
241#ifdef GXV_LOAD_UNUSED_VARS
242 defaultFlags = FT_NEXT_ULONG( p );
243#else
244 p += 4;
245#endif
246 chainLength = FT_NEXT_ULONG( p );
247 nFeatureFlags = FT_NEXT_USHORT( p );
248 nSubtables = FT_NEXT_USHORT( p );
249
250 gxv_mort_featurearray_validate( p, table + chainLength,
251 nFeatureFlags, gxvalid );
252 p += gxvalid->subtable_length;
253 gxv_mort_subtables_validate( p, table + chainLength, nSubtables, gxvalid );
254 gxvalid->subtable_length = chainLength;
255
256 /* TODO: validate defaultFlags */
257 GXV_EXIT;
258 }
259
260
261 FT_LOCAL_DEF( void )
262 gxv_mort_validate( FT_Bytes table,
263 FT_Face face,
264 FT_Validator ftvalid )
265 {
266 GXV_ValidatorRec gxvalidrec;
267 GXV_Validator gxvalid = &gxvalidrec;
268 FT_Bytes p = table;
269 FT_Bytes limit = 0;
270 FT_ULong version;
271 FT_ULong nChains;
272 FT_ULong i;
273
274
275 gxvalid->root = ftvalid;
276 gxvalid->face = face;
277 limit = gxvalid->root->limit;
278
279 FT_TRACE3(( "validating `mort' table\n" ));
280 GXV_INIT;
281
282 GXV_LIMIT_CHECK( 4 + 4 );
283 version = FT_NEXT_ULONG( p );
284 nChains = FT_NEXT_ULONG( p );
285
286 if (version != 0x00010000UL)
287 FT_INVALID_FORMAT;
288
289 for ( i = 0; i < nChains; i++ )
290 {
291 GXV_TRACE(( "validating chain %lu/%lu\n", i + 1, nChains ));
292 GXV_32BIT_ALIGNMENT_VALIDATE( p - table );
293 gxv_mort_chain_validate( p, limit, gxvalid );
294 p += gxvalid->subtable_length;
295 }
296
297 FT_TRACE4(( "\n" ));
298 }
299
300
301/* END */
302