/src/freetype/src/gxvalid/gxvmort2.c
C | 311 lines | 211 code | 63 blank | 37 comment | 11 complexity | 2e44d40e897a796227c73fe3d984b265 MD5 | raw file
1/***************************************************************************/ 2/* */ 3/* gxvmort2.c */ 4/* */ 5/* TrueTypeGX/AAT mort table validation */ 6/* body for type2 (Ligature Substitution) subtable. */ 7/* */ 8/* Copyright 2005 by 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 30 31 /*************************************************************************/ 32 /* */ 33 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ 34 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ 35 /* messages during execution. */ 36 /* */ 37#undef FT_COMPONENT 38#define FT_COMPONENT trace_gxvmort 39 40 41 typedef struct GXV_mort_subtable_type2_StateOptRec_ 42 { 43 FT_UShort ligActionTable; 44 FT_UShort componentTable; 45 FT_UShort ligatureTable; 46 FT_UShort ligActionTable_length; 47 FT_UShort componentTable_length; 48 FT_UShort ligatureTable_length; 49 50 } GXV_mort_subtable_type2_StateOptRec, 51 *GXV_mort_subtable_type2_StateOptRecData; 52 53#define GXV_MORT_SUBTABLE_TYPE2_HEADER_SIZE \ 54 ( GXV_STATETABLE_HEADER_SIZE + 2 + 2 + 2 ) 55 56 57 static void 58 gxv_mort_subtable_type2_opttable_load( FT_Bytes table, 59 FT_Bytes limit, 60 GXV_Validator valid ) 61 { 62 FT_Bytes p = table; 63 GXV_mort_subtable_type2_StateOptRecData optdata = 64 (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata; 65 66 67 GXV_LIMIT_CHECK( 2 + 2 + 2 ); 68 optdata->ligActionTable = FT_NEXT_USHORT( p ); 69 optdata->componentTable = FT_NEXT_USHORT( p ); 70 optdata->ligatureTable = FT_NEXT_USHORT( p ); 71 72 GXV_TRACE(( "offset to ligActionTable=0x%04x\n", 73 optdata->ligActionTable )); 74 GXV_TRACE(( "offset to componentTable=0x%04x\n", 75 optdata->componentTable )); 76 GXV_TRACE(( "offset to ligatureTable=0x%04x\n", 77 optdata->ligatureTable )); 78 } 79 80 81 static void 82 gxv_mort_subtable_type2_subtable_setup( FT_UShort table_size, 83 FT_UShort classTable, 84 FT_UShort stateArray, 85 FT_UShort entryTable, 86 FT_UShort *classTable_length_p, 87 FT_UShort *stateArray_length_p, 88 FT_UShort *entryTable_length_p, 89 GXV_Validator valid ) 90 { 91 FT_UShort o[6]; 92 FT_UShort *l[6]; 93 FT_UShort buff[7]; 94 95 GXV_mort_subtable_type2_StateOptRecData optdata = 96 (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata; 97 98 99 GXV_NAME_ENTER( "subtable boundaries setup" ); 100 101 o[0] = classTable; 102 o[1] = stateArray; 103 o[2] = entryTable; 104 o[3] = optdata->ligActionTable; 105 o[4] = optdata->componentTable; 106 o[5] = optdata->ligatureTable; 107 l[0] = classTable_length_p; 108 l[1] = stateArray_length_p; 109 l[2] = entryTable_length_p; 110 l[3] = &(optdata->ligActionTable_length); 111 l[4] = &(optdata->componentTable_length); 112 l[5] = &(optdata->ligatureTable_length); 113 114 gxv_set_length_by_ushort_offset( o, l, buff, 6, table_size, valid ); 115 116 GXV_TRACE(( "classTable: offset=0x%04x length=0x%04x\n", 117 classTable, *classTable_length_p )); 118 GXV_TRACE(( "stateArray: offset=0x%04x length=0x%04x\n", 119 stateArray, *stateArray_length_p )); 120 GXV_TRACE(( "entryTable: offset=0x%04x length=0x%04x\n", 121 entryTable, *entryTable_length_p )); 122 GXV_TRACE(( "ligActionTable: offset=0x%04x length=0x%04x\n", 123 optdata->ligActionTable, 124 optdata->ligActionTable_length )); 125 GXV_TRACE(( "componentTable: offset=0x%04x length=0x%04x\n", 126 optdata->componentTable, 127 optdata->componentTable_length )); 128 GXV_TRACE(( "ligatureTable: offset=0x%04x length=0x%04x\n", 129 optdata->ligatureTable, 130 optdata->ligatureTable_length )); 131 132 GXV_EXIT; 133 } 134 135 136 static void 137 gxv_mort_subtable_type2_ligActionOffset_validate( 138 FT_Bytes table, 139 FT_UShort ligActionOffset, 140 GXV_Validator valid ) 141 { 142 /* access ligActionTable */ 143 GXV_mort_subtable_type2_StateOptRecData optdata = 144 (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata; 145 146 FT_Bytes lat_base = table + optdata->ligActionTable; 147 FT_Bytes p = table + ligActionOffset; 148 FT_Bytes lat_limit = lat_base + optdata->ligActionTable; 149 150 151 GXV_32BIT_ALIGNMENT_VALIDATE( ligActionOffset ); 152 if ( p < lat_base ) 153 { 154 GXV_TRACE(( "too short offset 0x%04x: p < lat_base (%d byte rewind)\n", 155 ligActionOffset, lat_base - p )); 156 157 /* FontValidator, ftxvalidator, ftxdumperfuser warn but continue */ 158 GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET ); 159 } 160 else if ( lat_limit < p ) 161 { 162 GXV_TRACE(( "too large offset 0x%04x: lat_limit < p (%d byte overrun)\n", 163 ligActionOffset, p - lat_limit )); 164 165 /* FontValidator, ftxvalidator, ftxdumperfuser warn but continue */ 166 GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET ); 167 } 168 else 169 { 170 /* validate entry in ligActionTable */ 171 FT_ULong lig_action; 172#ifdef GXV_LOAD_UNUSED_VARS 173 FT_UShort last; 174 FT_UShort store; 175#endif 176 FT_ULong offset; 177 178 179 lig_action = FT_NEXT_ULONG( p ); 180#ifdef GXV_LOAD_UNUSED_VARS 181 last = (FT_UShort)( ( lig_action >> 31 ) & 1 ); 182 store = (FT_UShort)( ( lig_action >> 30 ) & 1 ); 183#endif 184 185 /* Apple spec defines this offset as a word offset */ 186 offset = lig_action & 0x3FFFFFFFUL; 187 if ( offset * 2 < optdata->ligatureTable ) 188 { 189 GXV_TRACE(( "too short offset 0x%08x:" 190 " 2 x offset < ligatureTable (%d byte rewind)\n", 191 offset, optdata->ligatureTable - offset * 2 )); 192 193 GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET ); 194 } else if ( offset * 2 > 195 optdata->ligatureTable + optdata->ligatureTable_length ) 196 { 197 GXV_TRACE(( "too long offset 0x%08x:" 198 " 2 x offset > ligatureTable + ligatureTable_length" 199 " (%d byte overrun)\n", 200 offset, 201 optdata->ligatureTable + optdata->ligatureTable_length 202 - offset * 2 )); 203 204 GXV_SET_ERR_IF_PARANOID( FT_INVALID_OFFSET ); 205 } 206 } 207 } 208 209 210 static void 211 gxv_mort_subtable_type2_entry_validate( 212 FT_Byte state, 213 FT_UShort flags, 214 GXV_StateTable_GlyphOffsetCPtr glyphOffset_p, 215 FT_Bytes table, 216 FT_Bytes limit, 217 GXV_Validator valid ) 218 { 219#ifdef GXV_LOAD_UNUSED_VARS 220 FT_UShort setComponent; 221 FT_UShort dontAdvance; 222#endif 223 FT_UShort offset; 224 225 FT_UNUSED( state ); 226 FT_UNUSED( glyphOffset_p ); 227 FT_UNUSED( limit ); 228 229 230#ifdef GXV_LOAD_UNUSED_VARS 231 setComponent = (FT_UShort)( ( flags >> 15 ) & 1 ); 232 dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1 ); 233#endif 234 235 offset = (FT_UShort)( flags & 0x3FFFU ); 236 237 if ( 0 < offset ) 238 gxv_mort_subtable_type2_ligActionOffset_validate( table, offset, 239 valid ); 240 } 241 242 243 static void 244 gxv_mort_subtable_type2_ligatureTable_validate( FT_Bytes table, 245 GXV_Validator valid ) 246 { 247 GXV_mort_subtable_type2_StateOptRecData optdata = 248 (GXV_mort_subtable_type2_StateOptRecData)valid->statetable.optdata; 249 250 FT_Bytes p = table + optdata->ligatureTable; 251 FT_Bytes limit = table + optdata->ligatureTable 252 + optdata->ligatureTable_length; 253 254 255 GXV_NAME_ENTER( "mort chain subtable type2 - substitutionTable" ); 256 if ( 0 != optdata->ligatureTable ) 257 { 258 /* Apple does not give specification of ligatureTable format */ 259 while ( p < limit ) 260 { 261 FT_UShort lig_gid; 262 263 264 GXV_LIMIT_CHECK( 2 ); 265 lig_gid = FT_NEXT_USHORT( p ); 266 267 if ( valid->face->num_glyphs < lig_gid ) 268 GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID ); 269 } 270 } 271 GXV_EXIT; 272 } 273 274 275 FT_LOCAL_DEF( void ) 276 gxv_mort_subtable_type2_validate( FT_Bytes table, 277 FT_Bytes limit, 278 GXV_Validator valid ) 279 { 280 FT_Bytes p = table; 281 282 GXV_mort_subtable_type2_StateOptRec lig_rec; 283 284 285 GXV_NAME_ENTER( "mort chain subtable type2 (Ligature Substitution)" ); 286 287 GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE2_HEADER_SIZE ); 288 289 valid->statetable.optdata = 290 &lig_rec; 291 valid->statetable.optdata_load_func = 292 gxv_mort_subtable_type2_opttable_load; 293 valid->statetable.subtable_setup_func = 294 gxv_mort_subtable_type2_subtable_setup; 295 valid->statetable.entry_glyphoffset_fmt = 296 GXV_GLYPHOFFSET_NONE; 297 valid->statetable.entry_validate_func = 298 gxv_mort_subtable_type2_entry_validate; 299 300 gxv_StateTable_validate( p, limit, valid ); 301 302 p += valid->subtable_length; 303 gxv_mort_subtable_type2_ligatureTable_validate( table, valid ); 304 305 valid->subtable_length = p - table; 306 307 GXV_EXIT; 308 } 309 310 311/* END */