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 | |