1 | /**************************************************************************** |
2 | * |
3 | * gxvmort1.c |
4 | * |
5 | * TrueTypeGX/AAT mort table validation |
6 | * body for type1 (Contextual Substitution) subtable. |
7 | * |
8 | * Copyright (C) 2005-2023 by |
9 | * suzuki toshiya, Masatake YAMATO, Red Hat K.K., |
10 | * David Turner, Robert Wilhelm, and Werner Lemberg. |
11 | * |
12 | * This file is part of the FreeType project, and may only be used, |
13 | * modified, and distributed under the terms of the FreeType project |
14 | * license, LICENSE.TXT. By continuing to use, modify, or distribute |
15 | * this file you indicate that you have read the license and |
16 | * understand and accept it fully. |
17 | * |
18 | */ |
19 | |
20 | /**************************************************************************** |
21 | * |
22 | * gxvalid is derived from both gxlayout module and otvalid module. |
23 | * Development of gxlayout is supported by the Information-technology |
24 | * Promotion Agency(IPA), Japan. |
25 | * |
26 | */ |
27 | |
28 | |
29 | #include "gxvmort.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 | typedef struct GXV_mort_subtable_type1_StateOptRec_ |
43 | { |
44 | FT_UShort substitutionTable; |
45 | FT_UShort substitutionTable_length; |
46 | |
47 | } GXV_mort_subtable_type1_StateOptRec, |
48 | *GXV_mort_subtable_type1_StateOptRecData; |
49 | |
50 | #define \ |
51 | ( GXV_STATETABLE_HEADER_SIZE + 2 ) |
52 | |
53 | |
54 | static void |
55 | gxv_mort_subtable_type1_substitutionTable_load( FT_Bytes table, |
56 | FT_Bytes limit, |
57 | GXV_Validator gxvalid ) |
58 | { |
59 | FT_Bytes p = table; |
60 | |
61 | GXV_mort_subtable_type1_StateOptRecData optdata = |
62 | (GXV_mort_subtable_type1_StateOptRecData)gxvalid->statetable.optdata; |
63 | |
64 | |
65 | GXV_LIMIT_CHECK( 2 ); |
66 | optdata->substitutionTable = FT_NEXT_USHORT( p ); |
67 | } |
68 | |
69 | |
70 | static void |
71 | gxv_mort_subtable_type1_subtable_setup( FT_UShort table_size, |
72 | FT_UShort classTable, |
73 | FT_UShort stateArray, |
74 | FT_UShort entryTable, |
75 | FT_UShort* classTable_length_p, |
76 | FT_UShort* stateArray_length_p, |
77 | FT_UShort* entryTable_length_p, |
78 | GXV_Validator gxvalid ) |
79 | { |
80 | FT_UShort o[4]; |
81 | FT_UShort *l[4]; |
82 | FT_UShort buff[5]; |
83 | |
84 | GXV_mort_subtable_type1_StateOptRecData optdata = |
85 | (GXV_mort_subtable_type1_StateOptRecData)gxvalid->statetable.optdata; |
86 | |
87 | |
88 | o[0] = classTable; |
89 | o[1] = stateArray; |
90 | o[2] = entryTable; |
91 | o[3] = optdata->substitutionTable; |
92 | l[0] = classTable_length_p; |
93 | l[1] = stateArray_length_p; |
94 | l[2] = entryTable_length_p; |
95 | l[3] = &( optdata->substitutionTable_length ); |
96 | |
97 | gxv_set_length_by_ushort_offset( o, l, buff, 4, table_size, gxvalid ); |
98 | } |
99 | |
100 | |
101 | static void |
102 | gxv_mort_subtable_type1_offset_to_subst_validate( |
103 | FT_Short wordOffset, |
104 | const FT_String* tag, |
105 | FT_Byte state, |
106 | GXV_Validator gxvalid ) |
107 | { |
108 | FT_UShort substTable; |
109 | FT_UShort substTable_limit; |
110 | |
111 | FT_UNUSED( tag ); |
112 | FT_UNUSED( state ); |
113 | |
114 | |
115 | substTable = |
116 | ((GXV_mort_subtable_type1_StateOptRec *) |
117 | (gxvalid->statetable.optdata))->substitutionTable; |
118 | substTable_limit = |
119 | (FT_UShort)( substTable + |
120 | ((GXV_mort_subtable_type1_StateOptRec *) |
121 | (gxvalid->statetable.optdata))->substitutionTable_length ); |
122 | |
123 | gxvalid->min_gid = (FT_UShort)( ( substTable - wordOffset * 2 ) / 2 ); |
124 | gxvalid->max_gid = (FT_UShort)( ( substTable_limit - wordOffset * 2 ) / 2 ); |
125 | gxvalid->max_gid = (FT_UShort)( FT_MAX( gxvalid->max_gid, |
126 | gxvalid->face->num_glyphs ) ); |
127 | |
128 | /* XXX: check range? */ |
129 | |
130 | /* TODO: min_gid & max_gid comparison with ClassTable contents */ |
131 | } |
132 | |
133 | |
134 | static void |
135 | gxv_mort_subtable_type1_entry_validate( |
136 | FT_Byte state, |
137 | FT_UShort flags, |
138 | GXV_StateTable_GlyphOffsetCPtr glyphOffset_p, |
139 | FT_Bytes table, |
140 | FT_Bytes limit, |
141 | GXV_Validator gxvalid ) |
142 | { |
143 | #ifdef GXV_LOAD_UNUSED_VARS |
144 | FT_UShort setMark; |
145 | FT_UShort dontAdvance; |
146 | #endif |
147 | FT_UShort reserved; |
148 | FT_Short markOffset; |
149 | FT_Short currentOffset; |
150 | |
151 | FT_UNUSED( table ); |
152 | FT_UNUSED( limit ); |
153 | |
154 | |
155 | #ifdef GXV_LOAD_UNUSED_VARS |
156 | setMark = (FT_UShort)( flags >> 15 ); |
157 | dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1 ); |
158 | #endif |
159 | reserved = (FT_UShort)( flags & 0x3FFF ); |
160 | |
161 | markOffset = (FT_Short)( glyphOffset_p->ul >> 16 ); |
162 | currentOffset = (FT_Short)( glyphOffset_p->ul ); |
163 | |
164 | if ( 0 < reserved ) |
165 | { |
166 | GXV_TRACE(( " non-zero bits found in reserved range\n" )); |
167 | GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); |
168 | } |
169 | |
170 | gxv_mort_subtable_type1_offset_to_subst_validate( markOffset, |
171 | "markOffset" , |
172 | state, |
173 | gxvalid ); |
174 | |
175 | gxv_mort_subtable_type1_offset_to_subst_validate( currentOffset, |
176 | "currentOffset" , |
177 | state, |
178 | gxvalid ); |
179 | } |
180 | |
181 | |
182 | static void |
183 | gxv_mort_subtable_type1_substTable_validate( FT_Bytes table, |
184 | FT_Bytes limit, |
185 | GXV_Validator gxvalid ) |
186 | { |
187 | FT_Bytes p = table; |
188 | FT_UShort num_gids = (FT_UShort)( |
189 | ((GXV_mort_subtable_type1_StateOptRec *) |
190 | (gxvalid->statetable.optdata))->substitutionTable_length / 2 ); |
191 | FT_UShort i; |
192 | |
193 | |
194 | GXV_NAME_ENTER( "validating contents of substitutionTable" ); |
195 | for ( i = 0; i < num_gids; i++ ) |
196 | { |
197 | FT_UShort dst_gid; |
198 | |
199 | |
200 | GXV_LIMIT_CHECK( 2 ); |
201 | dst_gid = FT_NEXT_USHORT( p ); |
202 | |
203 | if ( dst_gid >= 0xFFFFU ) |
204 | continue; |
205 | |
206 | if ( dst_gid < gxvalid->min_gid || gxvalid->max_gid < dst_gid ) |
207 | { |
208 | GXV_TRACE(( "substTable include a strange gid[%d]=%d >" |
209 | " out of define range (%d..%d)\n" , |
210 | i, dst_gid, gxvalid->min_gid, gxvalid->max_gid )); |
211 | GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID ); |
212 | } |
213 | } |
214 | |
215 | GXV_EXIT; |
216 | } |
217 | |
218 | |
219 | /* |
220 | * subtable for Contextual glyph substitution is a modified StateTable. |
221 | * In addition to classTable, stateArray, and entryTable, the field |
222 | * `substitutionTable' is added. |
223 | */ |
224 | FT_LOCAL_DEF( void ) |
225 | gxv_mort_subtable_type1_validate( FT_Bytes table, |
226 | FT_Bytes limit, |
227 | GXV_Validator gxvalid ) |
228 | { |
229 | FT_Bytes p = table; |
230 | |
231 | GXV_mort_subtable_type1_StateOptRec st_rec; |
232 | |
233 | |
234 | GXV_NAME_ENTER( "mort chain subtable type1 (Contextual Glyph Subst)" ); |
235 | |
236 | GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE1_HEADER_SIZE ); |
237 | |
238 | gxvalid->statetable.optdata = |
239 | &st_rec; |
240 | gxvalid->statetable.optdata_load_func = |
241 | gxv_mort_subtable_type1_substitutionTable_load; |
242 | gxvalid->statetable.subtable_setup_func = |
243 | gxv_mort_subtable_type1_subtable_setup; |
244 | gxvalid->statetable.entry_glyphoffset_fmt = |
245 | GXV_GLYPHOFFSET_ULONG; |
246 | gxvalid->statetable.entry_validate_func = |
247 | |
248 | gxv_mort_subtable_type1_entry_validate; |
249 | gxv_StateTable_validate( p, limit, gxvalid ); |
250 | |
251 | gxv_mort_subtable_type1_substTable_validate( |
252 | table + st_rec.substitutionTable, |
253 | table + st_rec.substitutionTable + st_rec.substitutionTable_length, |
254 | gxvalid ); |
255 | |
256 | GXV_EXIT; |
257 | } |
258 | |
259 | |
260 | /* END */ |
261 | |