1 /***************************************************************************/ 2 /* */ 3 /* gxvmort.c */ 4 /* */ 5 /* TrueTypeGX/AAT mort table validation (body). */ 6 /* */ 7 /* Copyright 2005-2018 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 trace_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 ); 126 127 #ifdef FT_DEBUG_LEVEL_TRACE 128 if ( coverage & 0x8000U ) 129 GXV_TRACE(( " this subtable is for vertical text only\n" )); 130 else 131 GXV_TRACE(( " this subtable is for horizontal text only\n" )); 132 133 if ( coverage & 0x4000 ) 134 GXV_TRACE(( " this subtable is applied to glyph array " 135 "in descending order\n" )); 136 else 137 GXV_TRACE(( " this subtable is applied to glyph array " 138 "in ascending order\n" )); 139 140 if ( coverage & 0x2000 ) 141 GXV_TRACE(( " this subtable is forcibly applied to " 142 "vertical/horizontal text\n" )); 143 144 if ( coverage & 0x1FF8 ) 145 GXV_TRACE(( " coverage has non-zero bits in reserved area\n" )); 146 #endif 147 } 148 149 150 static void 151 gxv_mort_subtables_validate( FT_Bytes table, 152 FT_Bytes limit, 153 FT_UShort nSubtables, 154 GXV_Validator gxvalid ) 155 { 156 FT_Bytes p = table; 157 158 GXV_Validate_Func fmt_funcs_table[] = 159 { 160 gxv_mort_subtable_type0_validate, /* 0 */ 161 gxv_mort_subtable_type1_validate, /* 1 */ 162 gxv_mort_subtable_type2_validate, /* 2 */ 163 NULL, /* 3 */ 164 gxv_mort_subtable_type4_validate, /* 4 */ 165 gxv_mort_subtable_type5_validate, /* 5 */ 166 167 }; 168 169 FT_UShort i; 170 171 172 GXV_NAME_ENTER( "subtables in a chain" ); 173 174 for ( i = 0; i < nSubtables; i++ ) 175 { 176 GXV_Validate_Func func; 177 178 FT_UShort length; 179 FT_UShort coverage; 180 #ifdef GXV_LOAD_UNUSED_VARS 181 FT_ULong subFeatureFlags; 182 #endif 183 FT_UInt type; 184 FT_UInt rest; 185 186 187 GXV_LIMIT_CHECK( 2 + 2 + 4 ); 188 length = FT_NEXT_USHORT( p ); 189 coverage = FT_NEXT_USHORT( p ); 190 #ifdef GXV_LOAD_UNUSED_VARS 191 subFeatureFlags = FT_NEXT_ULONG( p ); 192 #else 193 p += 4; 194 #endif 195 196 GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n", 197 i + 1, nSubtables, length )); 198 type = coverage & 0x0007; 199 rest = length - ( 2 + 2 + 4 ); 200 201 GXV_LIMIT_CHECK( rest ); 202 gxv_mort_coverage_validate( coverage, gxvalid ); 203 204 if ( type > 5 ) 205 FT_INVALID_FORMAT; 206 207 func = fmt_funcs_table[type]; 208 if ( !func ) 209 GXV_TRACE(( "morx type %d is reserved\n", type )); 210 211 func( p, p + rest, gxvalid ); 212 213 p += rest; 214 /* TODO: validate subFeatureFlags */ 215 } 216 217 gxvalid->subtable_length = (FT_ULong)( p - table ); 218 219 GXV_EXIT; 220 } 221 222 223 static void 224 gxv_mort_chain_validate( FT_Bytes table, 225 FT_Bytes limit, 226 GXV_Validator gxvalid ) 227 { 228 FT_Bytes p = table; 229 #ifdef GXV_LOAD_UNUSED_VARS 230 FT_ULong defaultFlags; 231 #endif 232 FT_ULong chainLength; 233 FT_UShort nFeatureFlags; 234 FT_UShort nSubtables; 235 236 237 GXV_NAME_ENTER( "mort chain header" ); 238 239 GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 ); 240 #ifdef GXV_LOAD_UNUSED_VARS 241 defaultFlags = FT_NEXT_ULONG( p ); 242 #else 243 p += 4; 244 #endif 245 chainLength = FT_NEXT_ULONG( p ); 246 nFeatureFlags = FT_NEXT_USHORT( p ); 247 nSubtables = FT_NEXT_USHORT( p ); 248 249 gxv_mort_featurearray_validate( p, table + chainLength, 250 nFeatureFlags, gxvalid ); 251 p += gxvalid->subtable_length; 252 gxv_mort_subtables_validate( p, table + chainLength, nSubtables, gxvalid ); 253 gxvalid->subtable_length = chainLength; 254 255 /* TODO: validate defaultFlags */ 256 GXV_EXIT; 257 } 258 259 260 FT_LOCAL_DEF( void ) 261 gxv_mort_validate( FT_Bytes table, 262 FT_Face face, 263 FT_Validator ftvalid ) 264 { 265 GXV_ValidatorRec gxvalidrec; 266 GXV_Validator gxvalid = &gxvalidrec; 267 FT_Bytes p = table; 268 FT_Bytes limit = 0; 269 FT_ULong version; 270 FT_ULong nChains; 271 FT_ULong i; 272 273 274 gxvalid->root = ftvalid; 275 gxvalid->face = face; 276 limit = gxvalid->root->limit; 277 278 FT_TRACE3(( "validating `mort' table\n" )); 279 GXV_INIT; 280 281 GXV_LIMIT_CHECK( 4 + 4 ); 282 version = FT_NEXT_ULONG( p ); 283 nChains = FT_NEXT_ULONG( p ); 284 285 if (version != 0x00010000UL) 286 FT_INVALID_FORMAT; 287 288 for ( i = 0; i < nChains; i++ ) 289 { 290 GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains )); 291 GXV_32BIT_ALIGNMENT_VALIDATE( p - table ); 292 gxv_mort_chain_validate( p, limit, gxvalid ); 293 p += gxvalid->subtable_length; 294 } 295 296 FT_TRACE4(( "\n" )); 297 } 298 299 300 /* END */ 301
