lib/taname.c

   1 /* taname.c */
   2
   3 /*
   4  * Copyright (C) 2012 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 = *(p++) << 8;
  66   n->format += *(p++);
  67   n->name_count = *(p++) << 8;
  68   n->name_count += *(p++);
  69   n->string_offset = *(p++) << 8;
  70   n->string_offset += *(p++);
  71
  72   n->name_records = NULL;
  73   n->lang_tag_records = NULL;
  74
  75   /* all name strings must be between `startp' and `endp' */
  76   startp = buf + 6 + 12 * n->name_count;
  77   endp = buf + buf_len;
  78
  79   /* format 1 also has language tag records */
  80   if (n->format == 1)
  81   {
  82     FT_Byte* q;
  83
  84
  85     q = startp;
  86     if (q + 2 > endp)
  87       return FT_Err_Invalid_Table;
  88
  89     n->lang_tag_count = *(q++) << 8;
  90     n->lang_tag_count += *q;
  91
  92     startp += 2 + 4 * n->lang_tag_count;
  93   }
  94   else
  95     n->lang_tag_count = 0;
  96
  97   if (startp > endp)
  98     return FT_Err_Invalid_Table;
  99
 100   *start = startp;
 101   *end = endp;
 102   *curp = p;
 103
 104   return TA_Err_Ok;
 105 }
 106
 107
 108 static FT_Error
 109 parse_name_records(FT_Byte** curp,
 110                    Naming_Table* n,
 111                    FT_Byte* buf,
 112                    FT_Byte* startp,
 113                    FT_Byte* endp,
 114                    FONT* font)
 115 {
 116   FT_UShort i, count;
 117   FT_Byte* p;
 118
 119
 120   p = *curp;
 121
 122   if (!n->name_count)
 123     return TA_Err_Ok;
 124
 125   /* allocate name records array */
 126   n->name_records = (Name_Record*)calloc(1, n->name_count
 127                                             * sizeof (Name_Record));
 128   if (!n->name_records)
 129     return FT_Err_Out_Of_Memory;
 130
 131   /* walk over all name records */
 132   count = 0;
 133   for (i = 0; i < n->name_count; i++)
 134   {
 135     Name_Record* r = &n->name_records[count];
 136
 137     FT_UShort offset;
 138     FT_Byte* s;
 139     FT_UShort l;
 140
 141
 142     r->platform_id = *(p++) << 8;
 143     r->platform_id += *(p++);
 144     r->encoding_id = *(p++) << 8;
 145     r->encoding_id += *(p++);
 146     r->language_id = *(p++) << 8;
 147     r->language_id += *(p++);
 148     r->name_id = *(p++) << 8;
 149     r->name_id += *(p++);
 150
 151     r->len = *(p++) << 8;
 152     r->len += *(p++);
 153
 154     offset = *(p++) << 8;
 155     offset += *(p++);
 156
 157     s = buf + n->string_offset + offset;
 158
 159     /* ignore invalid entries */
 160     if (s < startp || s + r->len > endp)
 161       continue;
 162
 163     /* mac encoding or non-Unicode Windows encoding? */
 164     if (r->platform_id == 1
 165         || (r->platform_id == 3 && !(r->encoding_id == 1
 166                                      || r->encoding_id == 10)))
 167     {
 168       /* one-byte or multi-byte encodings */
 169
 170       /* skip everything after a NULL byte (if any) */
 171       for (l = 0; l < r->len; l++)
 172         if (!s[l])
 173           break;
 174
 175       /* ignore zero-length entries */
 176       if (!l)
 177         continue;
 178
 179       r->len = l;
 180     }
 181     else
 182     {
 183       /* (two-byte) UTF-16BE for everything else */
 184
 185       /* we need an even number of bytes */
 186       r->len &= ~1;
 187
 188       /* ignore entries which contain only NULL bytes */
 189       for (l = 0; l < r->len; l++)
 190         if (s[l])
 191           break;
 192       if (l == r->len)
 193         continue;
 194     }
 195
 196     r->str = (FT_Byte*)malloc(r->len);
 197     if (!r->str)
 198       return FT_Err_Out_Of_Memory;
 199     memcpy(r->str, s, r->len);
 200
 201     if (font->info)
 202     {
 203       if (font->info(r->platform_id,
 204                      r->encoding_id,
 205                      r->language_id,
 206                      r->name_id,
 207                      &r->len,
 208                      &r->str,
 209                      font->info_data))
 210         continue;
 211     }
 212     count++;
 213   }
 214
 215   /* shrink name record array if necessary */
 216   n->name_records = (Name_Record*)realloc(n->name_records,
 217                                           count * sizeof (Name_Record));
 218   n->name_count = count;
 219
 220   return TA_Err_Ok;
 221 }
 222
 223
 224 FT_Error
 225 parse_lang_tag_records(FT_Byte** curp,
 226                        Naming_Table* n,
 227                        FT_Byte* buf,
 228                        FT_Byte* startp,
 229                        FT_Byte* endp)
 230 {
 231   FT_UShort i;
 232   FT_Byte* p;
 233
 234
 235   p = *curp;
 236
 237   if (!n->lang_tag_count)
 238     return TA_Err_Ok;
 239
 240   /* allocate language tags array */
 241   n->lang_tag_records = (Lang_Tag_Record*)calloc(
 242                           1, n->lang_tag_count * sizeof (Lang_Tag_Record));
 243   if (!n->lang_tag_records)
 244     return FT_Err_Out_Of_Memory;
 245
 246   /* walk over all language tag records (if any) */
 247   for (i = 0; i < n->lang_tag_count; i++)
 248   {
 249     Lang_Tag_Record* r = &n->lang_tag_records[i];
 250
 251     FT_UShort offset;
 252     FT_Byte* s;
 253
 254
 255     r->len = *(p++) << 8;
 256     r->len += *(p++);
 257
 258     offset = *(p++) << 8;
 259     offset += *(p++);
 260
 261     s = buf + n->string_offset + offset;
 262
 263     /* ignore an invalid entry -- */
 264     /* contrary to name records, we can't simply remove it */
 265     /* because references to it should still work */
 266     /* (we don't apply more fixes */
 267     /* since ttfautohint is not a TrueType sanitizing tool) */
 268     if (s < startp || s + r->len > endp)
 269       continue;
 270
 271     /* we don't massage the data since we only make a copy */
 272     r->str = (FT_Byte*)malloc(r->len);
 273     if (!r->str)
 274       return FT_Err_Out_Of_Memory;
 275
 276     memcpy(r->str, s, r->len);
 277   }
 278
 279   return TA_Err_Ok;
 280 }
 281
 282
 283 /* we build a non-optimized `name' table, this is, */
 284 /* we don't fold strings `foo' and `foobar' into one string */
 285
 286 static FT_Error
 287 build_name_table(Naming_Table* n,
 288                  SFNT_Table* name_table)
 289 {
 290   FT_Byte* buf_new;
 291   FT_Byte* buf_new_resized;
 292   FT_ULong buf_new_len;
 293   FT_ULong len;
 294
 295   FT_Byte* p;
 296   FT_Byte* q;
 297   FT_Byte* base;
 298
 299   FT_UShort i;
 300   FT_UShort string_offset;
 301   FT_ULong data_offset;
 302   FT_ULong data_len;
 303
 304
 305   /* we reallocate the array to its real size later on */
 306   buf_new_len= 6 + 12 * n->name_count;
 307   if (n->format == 1)
 308     buf_new_len += 2 + 4 * n->lang_tag_count;
 309
 310   buf_new = (FT_Byte*)malloc(buf_new_len);
 311   if (!buf_new)
 312     return FT_Err_Out_Of_Memory;
 313
 314   /* note that the OpenType specification says that `string_offset' is the */
 315   /* `offset to the start of string storage (from start of table)', */
 316   /* but this isn't enforced by the major rendering engines */
 317   /* as long as the final string offsets are valid */
 318   string_offset = (buf_new_len <= 0xFFFF) ? buf_new_len : 0xFFFF;
 319
 320   p = buf_new;
 321
 322   *(p++) = HIGH(n->format);
 323   *(p++) = LOW(n->format);
 324   *(p++) = HIGH(n->name_count);
 325   *(p++) = LOW(n->name_count);
 326   *(p++) = HIGH(string_offset);
 327   *(p++) = LOW(string_offset);
 328
 329   /* first pass */
 330
 331   data_len = 0;
 332   for (i = 0; i < n->name_count; i++)
 333   {
 334     Name_Record* r = &n->name_records[i];
 335
 336
 337     *(p++) = HIGH(r->platform_id);
 338     *(p++) = LOW(r->platform_id);
 339     *(p++) = HIGH(r->encoding_id);
 340     *(p++) = LOW(r->encoding_id);
 341     *(p++) = HIGH(r->language_id);
 342     *(p++) = LOW(r->language_id);
 343     *(p++) = HIGH(r->name_id);
 344     *(p++) = LOW(r->name_id);
 345
 346     *(p++) = HIGH(r->len);
 347     *(p++) = LOW(r->len);
 348
 349     /* the offset field gets filled in later */
 350     p += 2;
 351
 352     data_len += r->len;
 353   }
 354
 355   if (n->format == 1)
 356   {
 357     *(p++) = HIGH(n->lang_tag_count);
 358     *(p++) = LOW(n->lang_tag_count);
 359
 360     for (i = 0; i < n->lang_tag_count; i++)
 361     {
 362       Lang_Tag_Record* r = &n->lang_tag_records[i];
 363
 364
 365       *(p++) = HIGH(r->len);
 366       *(p++) = LOW(r->len);
 367
 368       /* the offset field gets filled in later */
 369       p += 2;
 370
 371       data_len += r->len;
 372     }
 373   }
 374
 375   if (buf_new_len + data_len > 2 * 0xFFFF)
 376   {
 377     /* the table would become too large, so we do nothing */
 378     free(buf_new);
 379     return TA_Err_Ok;
 380   }
 381
 382   data_offset = buf_new_len;
 383
 384   /* reallocate the buffer to fit its real size */
 385   buf_new_len += data_len;
 386   /* make the allocated buffer length a multiple of 4 */
 387   len = (buf_new_len + 3) & ~3;
 388
 389   buf_new_resized = (FT_Byte*)realloc(buf_new, len);
 390   if (!buf_new_resized)
 391   {
 392     free(buf_new);
 393     return FT_Err_Out_Of_Memory;
 394   }
 395   buf_new = buf_new_resized;
 396
 397   base = buf_new + string_offset;
 398   p = buf_new + data_offset;
 399
 400   /* second pass */
 401
 402   /* the first name record offset */
 403   q = &buf_new[6 + 10];
 404   for (i = 0; i < n->name_count; i++)
 405   {
 406     Name_Record* r = &n->name_records[i];
 407
 408
 409     /* fill in offset */
 410     *q = HIGH(p - base);
 411     *(q + 1) = LOW(p - base);
 412
 413     /* copy string */
 414     memcpy(p, r->str, r->len);
 415
 416     p += r->len;
 417     q += 12;
 418   }
 419
 420   if (n->format == 1)
 421   {
 422     /* the first language tag record offset */
 423     q = &buf_new[6 + 12 * n->name_count + 2 + 2];
 424     for (i = 0; i < n->lang_tag_count; i++)
 425     {
 426       Lang_Tag_Record* r = &n->lang_tag_records[i];
 427
 428
 429       /* fill in offset */
 430       *q = HIGH(p - base);
 431       *(q + 1) = LOW(p - base);
 432
 433       /* copy string */
 434       memcpy(p, r->str, r->len);
 435
 436       p += r->len;
 437       q += 4;
 438     }
 439   }
 440
 441   /* pad end of buffer with zeros */
 442   switch (buf_new_len % 4)
 443   {
 444   case 1:
 445     *(p++) = 0x00;
 446   case 2:
 447     *(p++) = 0x00;
 448   case 3:
 449     *(p++) = 0x00;
 450   default:
 451     break;
 452   }
 453
 454   /* we are done; replace the old buffer with the new one */
 455   free(name_table->buf);
 456
 457   name_table->buf = buf_new;
 458   name_table->len = buf_new_len;
 459
 460   return TA_Err_Ok;
 461 }
 462
 463
 464 /* we handle the `name' table as optional; */
 465 /* if there are problems not related to allocation, */
 466 /* simply return (or continue, if possible) without signaling an error, */
 467 /* and the original `name' table is not modified */
 468
 469 FT_Error
 470 TA_sfnt_update_name_table(SFNT* sfnt,
 471                           FONT* font)
 472 {
 473   FT_Error error;
 474
 475   SFNT_Table* name_table;
 476   FT_Byte* buf;
 477   FT_ULong buf_len;
 478
 479   Naming_Table n;
 480
 481   FT_Byte* p;
 482   FT_Byte* startp;
 483   FT_Byte* endp;
 484
 485   FT_UShort i;
 486
 487
 488   if (sfnt->name_idx == MISSING)
 489     return TA_Err_Ok;
 490
 491   name_table = &font->tables[sfnt->name_idx];
 492   buf = name_table->buf;
 493   buf_len = name_table->len;
 494
 495   if (name_table->processed)
 496     return TA_Err_Ok;
 497
 498   p = buf;
 499
 500   error = parse_name_header(&p, &n, buf_len, &startp, &endp);
 501   if (error)
 502     return TA_Err_Ok;
 503
 504   /* due to the structure of the `name' table, */
 505   /* we must parse it completely, apply our changes, */
 506   /* and rebuild it from scratch */
 507   error = parse_name_records(&p, &n, buf, startp, endp, font);
 508   if (error)
 509     goto Exit;
 510
 511   error = parse_lang_tag_records(&p, &n, buf, startp, endp);
 512   if (error)
 513     goto Exit;
 514
 515   error = build_name_table(&n, name_table);
 516   if (error)
 517     goto Exit;
 518
 519   name_table->checksum = TA_table_compute_checksum(name_table->buf,
 520                                                    name_table->len);
 521
 522 Exit:
 523   for (i = 0; i < n.name_count; i++)
 524     free(n.name_records[i].str);
 525   for (i = 0; i < n.lang_tag_count; i++)
 526     free(n.lang_tag_records[i].str);
 527
 528   free(n.name_records);
 529   free(n.lang_tag_records);
 530
 531   name_table->processed = 1;
 532
 533   return error;
 534 }
 535
 536 /* end of taname.c */