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1 /***************************************************************************/
2 /*                                                                         */
3 /*  ftbzip2.c                                                              */
4 /*                                                                         */
5 /*    FreeType support for .bz2 compressed files.                          */
6 /*                                                                         */
7 /*  This optional component relies on libbz2.  It should mainly be used to */
8 /*  parse compressed PCF fonts, as found with many X11 server              */
9 /*  distributions.                                                         */
10 /*                                                                         */
11 /*  Copyright 2010-2015 by                                                 */
12 /*  Joel Klinghed.                                                         */
13 /*                                                                         */
14 /*  based on `src/gzip/ftgzip.c'                                           */
15 /*                                                                         */
16 /*  This file is part of the FreeType project, and may only be used,       */
17 /*  modified, and distributed under the terms of the FreeType project      */
18 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
19 /*  this file you indicate that you have read the license and              */
20 /*  understand and accept it fully.                                        */
21 /*                                                                         */
22 /***************************************************************************/
23 
24 
25 #include <ft2build.h>
26 #include FT_INTERNAL_MEMORY_H
27 #include FT_INTERNAL_STREAM_H
28 #include FT_INTERNAL_DEBUG_H
29 #include FT_BZIP2_H
30 #include FT_CONFIG_STANDARD_LIBRARY_H
31 
32 
33 #include FT_MODULE_ERRORS_H
34 
35 #undef __FTERRORS_H__
36 
37 #undef  FT_ERR_PREFIX
38 #define FT_ERR_PREFIX  Bzip2_Err_
39 #define FT_ERR_BASE    FT_Mod_Err_Bzip2
40 
41 #include FT_ERRORS_H
42 
43 
44 #ifdef FT_CONFIG_OPTION_USE_BZIP2
45 
46 #ifdef FT_CONFIG_OPTION_PIC
47 #error "bzip2 code does not support PIC yet"
48 #endif
49 
50 #define BZ_NO_STDIO /* Do not need FILE */
51 #include <bzlib.h>
52 
53 
54 /***************************************************************************/
55 /***************************************************************************/
56 /*****                                                                 *****/
57 /*****           B Z I P 2   M E M O R Y   M A N A G E M E N T         *****/
58 /*****                                                                 *****/
59 /***************************************************************************/
60 /***************************************************************************/
61 
62   /* it is better to use FreeType memory routines instead of raw
63      'malloc/free' */
64 
65   typedef void *(* alloc_func)(void*, int, int);
66   typedef void (* free_func)(void*, void*);
67 
68   static void*
ft_bzip2_alloc(FT_Memory memory,int items,int size)69   ft_bzip2_alloc( FT_Memory  memory,
70                   int        items,
71                   int        size )
72   {
73     FT_ULong    sz = (FT_ULong)size * (FT_ULong)items;
74     FT_Error    error;
75     FT_Pointer  p  = NULL;
76 
77 
78     (void)FT_ALLOC( p, sz );
79     return p;
80   }
81 
82 
83   static void
ft_bzip2_free(FT_Memory memory,void * address)84   ft_bzip2_free( FT_Memory  memory,
85                  void*      address )
86   {
87     FT_MEM_FREE( address );
88   }
89 
90 
91 /***************************************************************************/
92 /***************************************************************************/
93 /*****                                                                 *****/
94 /*****              B Z I P 2   F I L E   D E S C R I P T O R          *****/
95 /*****                                                                 *****/
96 /***************************************************************************/
97 /***************************************************************************/
98 
99 #define FT_BZIP2_BUFFER_SIZE  4096
100 
101   typedef struct  FT_BZip2FileRec_
102   {
103     FT_Stream  source;         /* parent/source stream        */
104     FT_Stream  stream;         /* embedding stream            */
105     FT_Memory  memory;         /* memory allocator            */
106     bz_stream  bzstream;       /* bzlib input stream          */
107 
108     FT_Byte    input[FT_BZIP2_BUFFER_SIZE];  /* input read buffer  */
109 
110     FT_Byte    buffer[FT_BZIP2_BUFFER_SIZE]; /* output buffer      */
111     FT_ULong   pos;                          /* position in output */
112     FT_Byte*   cursor;
113     FT_Byte*   limit;
114 
115   } FT_BZip2FileRec, *FT_BZip2File;
116 
117 
118   /* check and skip .bz2 header - we don't support `transparent' compression */
119   static FT_Error
ft_bzip2_check_header(FT_Stream stream)120   ft_bzip2_check_header( FT_Stream  stream )
121   {
122     FT_Error  error = FT_Err_Ok;
123     FT_Byte   head[4];
124 
125 
126     if ( FT_STREAM_SEEK( 0 )       ||
127          FT_STREAM_READ( head, 4 ) )
128       goto Exit;
129 
130     /* head[0] && head[1] are the magic numbers;    */
131     /* head[2] is the version, and head[3] the blocksize */
132     if ( head[0] != 0x42  ||
133          head[1] != 0x5A  ||
134          head[2] != 0x68  )  /* only support bzip2 (huffman) */
135     {
136       error = FT_THROW( Invalid_File_Format );
137       goto Exit;
138     }
139 
140   Exit:
141     return error;
142   }
143 
144 
145   static FT_Error
ft_bzip2_file_init(FT_BZip2File zip,FT_Stream stream,FT_Stream source)146   ft_bzip2_file_init( FT_BZip2File  zip,
147                       FT_Stream     stream,
148                       FT_Stream     source )
149   {
150     bz_stream*  bzstream = &zip->bzstream;
151     FT_Error    error    = FT_Err_Ok;
152 
153 
154     zip->stream = stream;
155     zip->source = source;
156     zip->memory = stream->memory;
157 
158     zip->limit  = zip->buffer + FT_BZIP2_BUFFER_SIZE;
159     zip->cursor = zip->limit;
160     zip->pos    = 0;
161 
162     /* check .bz2 header */
163     {
164       stream = source;
165 
166       error = ft_bzip2_check_header( stream );
167       if ( error )
168         goto Exit;
169 
170       if ( FT_STREAM_SEEK( 0 ) )
171         goto Exit;
172     }
173 
174     /* initialize bzlib */
175     bzstream->bzalloc = (alloc_func)ft_bzip2_alloc;
176     bzstream->bzfree  = (free_func) ft_bzip2_free;
177     bzstream->opaque  = zip->memory;
178 
179     bzstream->avail_in = 0;
180     bzstream->next_in  = (char*)zip->buffer;
181 
182     if ( BZ2_bzDecompressInit( bzstream, 0, 0 ) != BZ_OK ||
183          bzstream->next_in == NULL                       )
184       error = FT_THROW( Invalid_File_Format );
185 
186   Exit:
187     return error;
188   }
189 
190 
191   static void
ft_bzip2_file_done(FT_BZip2File zip)192   ft_bzip2_file_done( FT_BZip2File  zip )
193   {
194     bz_stream*  bzstream = &zip->bzstream;
195 
196 
197     BZ2_bzDecompressEnd( bzstream );
198 
199     /* clear the rest */
200     bzstream->bzalloc   = NULL;
201     bzstream->bzfree    = NULL;
202     bzstream->opaque    = NULL;
203     bzstream->next_in   = NULL;
204     bzstream->next_out  = NULL;
205     bzstream->avail_in  = 0;
206     bzstream->avail_out = 0;
207 
208     zip->memory = NULL;
209     zip->source = NULL;
210     zip->stream = NULL;
211   }
212 
213 
214   static FT_Error
ft_bzip2_file_reset(FT_BZip2File zip)215   ft_bzip2_file_reset( FT_BZip2File  zip )
216   {
217     FT_Stream  stream = zip->source;
218     FT_Error   error;
219 
220 
221     if ( !FT_STREAM_SEEK( 0 ) )
222     {
223       bz_stream*  bzstream = &zip->bzstream;
224 
225 
226       BZ2_bzDecompressEnd( bzstream );
227 
228       bzstream->avail_in  = 0;
229       bzstream->next_in   = (char*)zip->input;
230       bzstream->avail_out = 0;
231       bzstream->next_out  = (char*)zip->buffer;
232 
233       zip->limit  = zip->buffer + FT_BZIP2_BUFFER_SIZE;
234       zip->cursor = zip->limit;
235       zip->pos    = 0;
236 
237       BZ2_bzDecompressInit( bzstream, 0, 0 );
238     }
239 
240     return error;
241   }
242 
243 
244   static FT_Error
ft_bzip2_file_fill_input(FT_BZip2File zip)245   ft_bzip2_file_fill_input( FT_BZip2File  zip )
246   {
247     bz_stream*  bzstream = &zip->bzstream;
248     FT_Stream   stream    = zip->source;
249     FT_ULong    size;
250 
251 
252     if ( stream->read )
253     {
254       size = stream->read( stream, stream->pos, zip->input,
255                            FT_BZIP2_BUFFER_SIZE );
256       if ( size == 0 )
257       {
258         zip->limit = zip->cursor;
259         return FT_THROW( Invalid_Stream_Operation );
260       }
261     }
262     else
263     {
264       size = stream->size - stream->pos;
265       if ( size > FT_BZIP2_BUFFER_SIZE )
266         size = FT_BZIP2_BUFFER_SIZE;
267 
268       if ( size == 0 )
269       {
270         zip->limit = zip->cursor;
271         return FT_THROW( Invalid_Stream_Operation );
272       }
273 
274       FT_MEM_COPY( zip->input, stream->base + stream->pos, size );
275     }
276     stream->pos += size;
277 
278     bzstream->next_in  = (char*)zip->input;
279     bzstream->avail_in = size;
280 
281     return FT_Err_Ok;
282   }
283 
284 
285   static FT_Error
ft_bzip2_file_fill_output(FT_BZip2File zip)286   ft_bzip2_file_fill_output( FT_BZip2File  zip )
287   {
288     bz_stream*  bzstream = &zip->bzstream;
289     FT_Error    error    = FT_Err_Ok;
290 
291 
292     zip->cursor         = zip->buffer;
293     bzstream->next_out  = (char*)zip->cursor;
294     bzstream->avail_out = FT_BZIP2_BUFFER_SIZE;
295 
296     while ( bzstream->avail_out > 0 )
297     {
298       int  err;
299 
300 
301       if ( bzstream->avail_in == 0 )
302       {
303         error = ft_bzip2_file_fill_input( zip );
304         if ( error )
305           break;
306       }
307 
308       err = BZ2_bzDecompress( bzstream );
309 
310       if ( err == BZ_STREAM_END )
311       {
312         zip->limit = (FT_Byte*)bzstream->next_out;
313         if ( zip->limit == zip->cursor )
314           error = FT_THROW( Invalid_Stream_Operation );
315         break;
316       }
317       else if ( err != BZ_OK )
318       {
319         zip->limit = zip->cursor;
320         error      = FT_THROW( Invalid_Stream_Operation );
321         break;
322       }
323     }
324 
325     return error;
326   }
327 
328 
329   /* fill output buffer; `count' must be <= FT_BZIP2_BUFFER_SIZE */
330   static FT_Error
ft_bzip2_file_skip_output(FT_BZip2File zip,FT_ULong count)331   ft_bzip2_file_skip_output( FT_BZip2File  zip,
332                              FT_ULong      count )
333   {
334     FT_Error  error = FT_Err_Ok;
335     FT_ULong  delta;
336 
337 
338     for (;;)
339     {
340       delta = (FT_ULong)( zip->limit - zip->cursor );
341       if ( delta >= count )
342         delta = count;
343 
344       zip->cursor += delta;
345       zip->pos    += delta;
346 
347       count -= delta;
348       if ( count == 0 )
349         break;
350 
351       error = ft_bzip2_file_fill_output( zip );
352       if ( error )
353         break;
354     }
355 
356     return error;
357   }
358 
359 
360   static FT_ULong
ft_bzip2_file_io(FT_BZip2File zip,FT_ULong pos,FT_Byte * buffer,FT_ULong count)361   ft_bzip2_file_io( FT_BZip2File  zip,
362                     FT_ULong      pos,
363                     FT_Byte*      buffer,
364                     FT_ULong      count )
365   {
366     FT_ULong  result = 0;
367     FT_Error  error;
368 
369 
370     /* Reset inflate stream if we're seeking backwards.        */
371     /* Yes, that is not too efficient, but it saves memory :-) */
372     if ( pos < zip->pos )
373     {
374       error = ft_bzip2_file_reset( zip );
375       if ( error )
376         goto Exit;
377     }
378 
379     /* skip unwanted bytes */
380     if ( pos > zip->pos )
381     {
382       error = ft_bzip2_file_skip_output( zip, (FT_ULong)( pos - zip->pos ) );
383       if ( error )
384         goto Exit;
385     }
386 
387     if ( count == 0 )
388       goto Exit;
389 
390     /* now read the data */
391     for (;;)
392     {
393       FT_ULong  delta;
394 
395 
396       delta = (FT_ULong)( zip->limit - zip->cursor );
397       if ( delta >= count )
398         delta = count;
399 
400       FT_MEM_COPY( buffer, zip->cursor, delta );
401       buffer      += delta;
402       result      += delta;
403       zip->cursor += delta;
404       zip->pos    += delta;
405 
406       count -= delta;
407       if ( count == 0 )
408         break;
409 
410       error = ft_bzip2_file_fill_output( zip );
411       if ( error )
412         break;
413     }
414 
415   Exit:
416     return result;
417   }
418 
419 
420 /***************************************************************************/
421 /***************************************************************************/
422 /*****                                                                 *****/
423 /*****               B Z   E M B E D D I N G   S T R E A M             *****/
424 /*****                                                                 *****/
425 /***************************************************************************/
426 /***************************************************************************/
427 
428   static void
ft_bzip2_stream_close(FT_Stream stream)429   ft_bzip2_stream_close( FT_Stream  stream )
430   {
431     FT_BZip2File  zip    = (FT_BZip2File)stream->descriptor.pointer;
432     FT_Memory     memory = stream->memory;
433 
434 
435     if ( zip )
436     {
437       /* finalize bzip file descriptor */
438       ft_bzip2_file_done( zip );
439 
440       FT_FREE( zip );
441 
442       stream->descriptor.pointer = NULL;
443     }
444   }
445 
446 
447   static unsigned long
ft_bzip2_stream_io(FT_Stream stream,unsigned long offset,unsigned char * buffer,unsigned long count)448   ft_bzip2_stream_io( FT_Stream       stream,
449                       unsigned long   offset,
450                       unsigned char*  buffer,
451                       unsigned long   count )
452   {
453     FT_BZip2File  zip = (FT_BZip2File)stream->descriptor.pointer;
454 
455 
456     return ft_bzip2_file_io( zip, offset, buffer, count );
457   }
458 
459 
460   FT_EXPORT_DEF( FT_Error )
FT_Stream_OpenBzip2(FT_Stream stream,FT_Stream source)461   FT_Stream_OpenBzip2( FT_Stream  stream,
462                        FT_Stream  source )
463   {
464     FT_Error      error;
465     FT_Memory     memory;
466     FT_BZip2File  zip = NULL;
467 
468 
469     if ( !stream || !source )
470     {
471       error = FT_THROW( Invalid_Stream_Handle );
472       goto Exit;
473     }
474 
475     memory = source->memory;
476 
477     /*
478      *  check the header right now; this prevents allocating unnecessary
479      *  objects when we don't need them
480      */
481     error = ft_bzip2_check_header( source );
482     if ( error )
483       goto Exit;
484 
485     FT_ZERO( stream );
486     stream->memory = memory;
487 
488     if ( !FT_QNEW( zip ) )
489     {
490       error = ft_bzip2_file_init( zip, stream, source );
491       if ( error )
492       {
493         FT_FREE( zip );
494         goto Exit;
495       }
496 
497       stream->descriptor.pointer = zip;
498     }
499 
500     stream->size  = 0x7FFFFFFFL;  /* don't know the real size! */
501     stream->pos   = 0;
502     stream->base  = 0;
503     stream->read  = ft_bzip2_stream_io;
504     stream->close = ft_bzip2_stream_close;
505 
506   Exit:
507     return error;
508   }
509 
510 #else  /* !FT_CONFIG_OPTION_USE_BZIP2 */
511 
512   FT_EXPORT_DEF( FT_Error )
FT_Stream_OpenBzip2(FT_Stream stream,FT_Stream source)513   FT_Stream_OpenBzip2( FT_Stream  stream,
514                        FT_Stream  source )
515   {
516     FT_UNUSED( stream );
517     FT_UNUSED( source );
518 
519     return FT_THROW( Unimplemented_Feature );
520   }
521 
522 #endif /* !FT_CONFIG_OPTION_USE_BZIP2 */
523 
524 
525 /* END */
526