lib/taname.c

   1 /* taname.c */
   2
   3 /*
   4  * Copyright (C) 2012-2017 by Werner Lemberg.
   5  *
   6  * This file is part of the ttfautohint library, and may only be used,
   7  * modified, and distributed under the terms given in `COPYING'.  By
   8  * continuing to use, modify, or distribute this file you indicate that you
   9  * have read `COPYING' and understand and accept it fully.
  10  *
  11  * The file `COPYING' mentioned in the previous paragraph is distributed
  12  * with the ttfautohint library.
  13  */
  14
  15
  16 #include <string.h>
  17 #include "ta.h"
  18
  19
  20 typedef struct Lang_Tag_Record_
  21 {
  22   FT_UShort len;
  23   FT_Byte* str;
  24 } Lang_Tag_Record;
  25
  26 typedef struct Name_Record_
  27 {
  28   FT_UShort platform_id;
  29   FT_UShort encoding_id;
  30   FT_UShort language_id;
  31   FT_UShort name_id;
  32
  33   FT_UShort len;
  34   FT_Byte* str;
  35 } Name_Record;
  36
  37 typedef struct Naming_Table_
  38 {
  39   FT_UShort format;
  40   FT_UShort string_offset;
  41
  42   FT_UShort name_count;
  43   Name_Record* name_records;
  44
  45   FT_UShort lang_tag_count;
  46   Lang_Tag_Record* lang_tag_records;
  47 } Naming_Table;
  48
  49
  50 static FT_Error
  51 parse_name_header(FT_Byte** curp,
  52                   Naming_Table* n,
  53                   FT_ULong buf_len,
  54                   FT_Byte** start,
  55                   FT_Byte** end)
  56 {
  57   FT_Byte* buf = *curp;
  58   FT_Byte* p;
  59   FT_Byte* startp;
  60   FT_Byte* endp;
  61
  62
  63   p = *curp;
  64
  65   n->format = NEXT_USHORT(p);
  66   n->name_count = NEXT_USHORT(p);
  67   n->string_offset = NEXT_USHORT(p);
  68
  69   n->name_records = NULL;
  70   n->lang_tag_records = NULL;
  71
  72   /* all name strings must be between `startp' and `endp' */
  73   startp = buf + 6 + 12 * n->name_count;
  74   endp = buf + buf_len;
  75
  76   /* format 1 also has language tag records */
  77   if (n->format == 1)
  78   {
  79     FT_Byte* q;
  80
  81
  82     q = startp;
  83     if (q + 2 > endp)
  84       return FT_Err_Invalid_Table;
  85
  86     n->lang_tag_count = NEXT_USHORT(q);
  87
  88     startp += 2 + 4 * n->lang_tag_count;
  89   }
  90   else
  91     n->lang_tag_count = 0;
  92
  93   if (startp > endp)
  94     return FT_Err_Invalid_Table;
  95
  96   *start = startp;
  97   *end = endp;
  98   *curp = p;
  99
 100   return TA_Err_Ok;
 101 }
 102
 103
 104 static FT_Error
 105 parse_name_records(FT_Byte** curp,
 106                    Naming_Table* n,
 107                    FT_Byte* buf,
 108                    FT_Byte* startp,
 109                    FT_Byte* endp,
 110                    FONT* font)
 111 {
 112   FT_UShort i, count;
 113   FT_Byte* p;
 114
 115
 116   p = *curp;
 117
 118   if (!n->name_count)
 119     return TA_Err_Ok;
 120
 121   /* allocate name records array */
 122   n->name_records = (Name_Record*)calloc(1, n->name_count
 123                                             * sizeof (Name_Record));
 124   if (!n->name_records)
 125     return FT_Err_Out_Of_Memory;
 126
 127   /* walk over all name records */
 128   count = 0;
 129   for (i = 0; i < n->name_count; i++)
 130   {
 131     Name_Record* r = &n->name_records[count];
 132
 133     FT_UShort offset;
 134     FT_Byte* s;
 135     FT_UShort l;
 136
 137
 138     r->platform_id = NEXT_USHORT(p);
 139     r->encoding_id = NEXT_USHORT(p);
 140     r->language_id = NEXT_USHORT(p);
 141     r->name_id = NEXT_USHORT(p);
 142
 143     r->len = NEXT_USHORT(p);
 144
 145     offset = NEXT_USHORT(p);
 146
 147     s = buf + n->string_offset + offset;
 148
 149     /* ignore invalid entries */
 150     if (s < startp || s + r->len > endp)
 151       continue;
 152
 153     /* mac encoding or non-Unicode Windows encoding? */
 154     if (r->platform_id == 1
 155         || (r->platform_id == 3 && !(r->encoding_id == 1
 156                                      || r->encoding_id == 10)))
 157     {
 158       /* one-byte or multi-byte encodings */
 159
 160       /* skip everything after a NULL byte (if any) */
 161       for (l = 0; l < r->len; l++)
 162         if (!s[l])
 163           break;
 164
 165       /* ignore zero-length entries */
 166       if (!l)
 167         continue;
 168
 169       r->len = l;
 170     }
 171     else
 172     {
 173       /* (two-byte) UTF-16BE for everything else */
 174
 175       /* we need an even number of bytes */
 176       r->len &= ~1U;
 177
 178       /* ignore entries which contain only NULL bytes */
 179       for (l = 0; l < r->len; l++)
 180         if (s[l])
 181           break;
 182       if (l == r->len)
 183         continue;
 184     }
 185
 186     r->str = (FT_Byte*)malloc(r->len);
 187     if (!r->str)
 188       return FT_Err_Out_Of_Memory;
 189     memcpy(r->str, s, r->len);
 190
 191     if (font->info)
 192     {
 193       /* we ignore the return value of `font->info' */
 194       font->info(r->platform_id,
 195                  r->encoding_id,
 196                  r->language_id,
 197                  r->name_id,
 198                  &r->len,
 199                  &r->str,
 200                  font->info_data);
 201     }
 202
 203     count++;
 204   }
 205
 206   /* let the user modify `name' table entries */
 207   if (font->info && font->info_post)
 208     /* we ignore the return value of `font->info_post' */
 209     font->info_post(font->info_data);
 210
 211   /* shrink name record array if necessary */
 212   n->name_records = (Name_Record*)realloc(n->name_records,
 213                                           count * sizeof (Name_Record));
 214   n->name_count = count;
 215
 216   return TA_Err_Ok;
 217 }
 218
 219
 220 static FT_Error
 221 parse_lang_tag_records(FT_Byte** curp,
 222                        Naming_Table* n,
 223                        FT_Byte* buf,
 224                        FT_Byte* startp,
 225                        FT_Byte* endp)
 226 {
 227   FT_UShort i;
 228   FT_Byte* p;
 229
 230
 231   p = *curp;
 232
 233   if (!n->lang_tag_count)
 234     return TA_Err_Ok;
 235
 236   /* allocate language tags array */
 237   n->lang_tag_records = (Lang_Tag_Record*)calloc(
 238                           1, n->lang_tag_count * sizeof (Lang_Tag_Record));
 239   if (!n->lang_tag_records)
 240     return FT_Err_Out_Of_Memory;
 241
 242   /* walk over all language tag records (if any) */
 243   for (i = 0; i < n->lang_tag_count; i++)
 244   {
 245     Lang_Tag_Record* r = &n->lang_tag_records[i];
 246
 247     FT_UShort offset;
 248     FT_Byte* s;
 249
 250
 251     r->len = NEXT_USHORT(p);
 252
 253     offset = NEXT_USHORT(p);
 254
 255     s = buf + n->string_offset + offset;
 256
 257     /* ignore an invalid entry -- */
 258     /* contrary to name records, we can't simply remove it */
 259     /* because references to it should still work */
 260     /* (we don't apply more fixes */
 261     /* since ttfautohint is not a TrueType sanitizing tool) */
 262     if (s < startp || s + r->len > endp)
 263       continue;
 264
 265     /* we don't massage the data since we only make a copy */
 266     r->str = (FT_Byte*)malloc(r->len);
 267     if (!r->str)
 268       return FT_Err_Out_Of_Memory;
 269
 270     memcpy(r->str, s, r->len);
 271   }
 272
 273   return TA_Err_Ok;
 274 }
 275
 276
 277 /* we build a non-optimized `name' table, this is, */
 278 /* we don't fold strings `foo' and `foobar' into one string */
 279
 280 static FT_Error
 281 build_name_table(Naming_Table* n,
 282                  SFNT_Table* name_table)
 283 {
 284   FT_Byte* buf_new;
 285   FT_Byte* buf_new_resized;
 286   FT_ULong buf_new_len;
 287   FT_ULong len;
 288
 289   FT_Byte* p;
 290   FT_Byte* q;
 291   FT_Byte* base;
 292
 293   FT_UShort i;
 294   FT_UShort string_offset;
 295   FT_ULong data_offset;
 296   FT_ULong data_len;
 297
 298
 299   /* we reallocate the array to its real size later on */
 300   buf_new_len= 6 + 12 * n->name_count;
 301   if (n->format == 1)
 302     buf_new_len += 2 + 4 * n->lang_tag_count;
 303
 304   buf_new = (FT_Byte*)malloc(buf_new_len);
 305   if (!buf_new)
 306     return FT_Err_Out_Of_Memory;
 307
 308   /* note that the OpenType specification says that `string_offset' is the */
 309   /* `offset to the start of string storage (from start of table)', */
 310   /* but this isn't enforced by the major rendering engines */
 311   /* as long as the final string offsets are valid */
 312   string_offset = (buf_new_len <= 0xFFFF) ? (FT_UShort)buf_new_len : 0xFFFF;
 313
 314   p = buf_new;
 315
 316   *(p++) = HIGH(n->format);
 317   *(p++) = LOW(n->format);
 318   *(p++) = HIGH(n->name_count);
 319   *(p++) = LOW(n->name_count);
 320   *(p++) = HIGH(string_offset);
 321   *(p++) = LOW(string_offset);
 322
 323   /* first pass */
 324
 325   data_len = 0;
 326   for (i = 0; i < n->name_count; i++)
 327   {
 328     Name_Record* r = &n->name_records[i];
 329
 330
 331     *(p++) = HIGH(r->platform_id);
 332     *(p++) = LOW(r->platform_id);
 333     *(p++) = HIGH(r->encoding_id);
 334     *(p++) = LOW(r->encoding_id);
 335     *(p++) = HIGH(r->language_id);
 336     *(p++) = LOW(r->language_id);
 337     *(p++) = HIGH(r->name_id);
 338     *(p++) = LOW(r->name_id);
 339
 340     *(p++) = HIGH(r->len);
 341     *(p++) = LOW(r->len);
 342
 343     /* the offset field gets filled in later */
 344     p += 2;
 345
 346     data_len += r->len;
 347   }
 348
 349   if (n->format == 1)
 350   {
 351     *(p++) = HIGH(n->lang_tag_count);
 352     *(p++) = LOW(n->lang_tag_count);
 353
 354     for (i = 0; i < n->lang_tag_count; i++)
 355     {
 356       Lang_Tag_Record* r = &n->lang_tag_records[i];
 357
 358
 359       *(p++) = HIGH(r->len);
 360       *(p++) = LOW(r->len);
 361
 362       /* the offset field gets filled in later */
 363       p += 2;
 364
 365       data_len += r->len;
 366     }
 367   }
 368
 369   if (buf_new_len + data_len > 2 * 0xFFFF)
 370   {
 371     /* the table would become too large, so we do nothing */
 372     free(buf_new);
 373     return TA_Err_Ok;
 374   }
 375
 376   data_offset = buf_new_len;
 377
 378   /* reallocate the buffer to fit its real size */
 379   buf_new_len += data_len;
 380   /* make the allocated buffer length a multiple of 4 */
 381   len = (buf_new_len + 3) & ~3U;
 382
 383   buf_new_resized = (FT_Byte*)realloc(buf_new, len);
 384   if (!buf_new_resized)
 385   {
 386     free(buf_new);
 387     return FT_Err_Out_Of_Memory;
 388   }
 389   buf_new = buf_new_resized;
 390
 391   base = buf_new + string_offset;
 392   p = buf_new + data_offset;
 393
 394   /* second pass */
 395
 396   /* the first name record offset */
 397   q = &buf_new[6 + 10];
 398   for (i = 0; i < n->name_count; i++)
 399   {
 400     Name_Record* r = &n->name_records[i];
 401
 402
 403     /* fill in offset */
 404     *q = HIGH(p - base);
 405     *(q + 1) = LOW(p - base);
 406
 407     /* copy string */
 408     memcpy(p, r->str, r->len);
 409
 410     p += r->len;
 411     q += 12;
 412   }
 413
 414   if (n->format == 1)
 415   {
 416     /* the first language tag record offset */
 417     q = &buf_new[6 + 12 * n->name_count + 2 + 2];
 418     for (i = 0; i < n->lang_tag_count; i++)
 419     {
 420       Lang_Tag_Record* r = &n->lang_tag_records[i];
 421
 422
 423       /* fill in offset */
 424       *q = HIGH(p - base);
 425       *(q + 1) = LOW(p - base);
 426
 427       /* copy string */
 428       memcpy(p, r->str, r->len);
 429
 430       p += r->len;
 431       q += 4;
 432     }
 433   }
 434
 435   /* pad end of buffer with zeros */
 436   switch (buf_new_len % 4)
 437   {
 438   case 1:
 439     *(p++) = 0x00;
 440   case 2:
 441     *(p++) = 0x00;
 442   case 3:
 443     *(p++) = 0x00;
 444   default:
 445     break;
 446   }
 447
 448   /* we are done; replace the old buffer with the new one */
 449   free(name_table->buf);
 450
 451   name_table->buf = buf_new;
 452   name_table->len = buf_new_len;
 453
 454   return TA_Err_Ok;
 455 }
 456
 457
 458 /* we handle the `name' table as optional; */
 459 /* if there are problems not related to allocation, */
 460 /* simply return (or continue, if possible) without signaling an error, */
 461 /* and the original `name' table is not modified */
 462
 463 FT_Error
 464 TA_sfnt_update_name_table(SFNT* sfnt,
 465                           FONT* font)
 466 {
 467   FT_Error error;
 468
 469   SFNT_Table* name_table;
 470   FT_Byte* buf;
 471   FT_ULong buf_len;
 472
 473   Naming_Table n;
 474
 475   FT_Byte* p;
 476   FT_Byte* startp;
 477   FT_Byte* endp;
 478
 479   FT_UShort i;
 480
 481
 482   if (sfnt->name_idx == MISSING)
 483     return TA_Err_Ok;
 484
 485   name_table = &font->tables[sfnt->name_idx];
 486   buf = name_table->buf;
 487   buf_len = name_table->len;
 488
 489   if (name_table->processed)
 490     return TA_Err_Ok;
 491
 492   p = buf;
 493
 494   error = parse_name_header(&p, &n, buf_len, &startp, &endp);
 495   if (error)
 496     return TA_Err_Ok;
 497
 498   /* due to the structure of the `name' table, */
 499   /* we must parse it completely, apply our changes, */
 500   /* and rebuild it from scratch */
 501   error = parse_name_records(&p, &n, buf, startp, endp, font);
 502   if (error)
 503     goto Exit;
 504
 505   error = parse_lang_tag_records(&p, &n, buf, startp, endp);
 506   if (error)
 507     goto Exit;
 508
 509   error = build_name_table(&n, name_table);
 510   if (error)
 511     goto Exit;
 512
 513   name_table->checksum = TA_table_compute_checksum(name_table->buf,
 514                                                    name_table->len);
 515
 516 Exit:
 517   for (i = 0; i < n.name_count; i++)
 518     free(n.name_records[i].str);
 519   for (i = 0; i < n.lang_tag_count; i++)
 520     free(n.lang_tag_records[i].str);
 521
 522   free(n.name_records);
 523   free(n.lang_tag_records);
 524
 525   name_table->processed = 1;
 526
 527   return error;
 528 }
 529
 530 /* end of taname.c */