Commit | Line | Data |
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93509525 | 1 | /* Low-level I/O routines for BFDs. |
7c192733 AC |
2 | |
3 | Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
3db64b00 | 4 | 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
9553c638 | 5 | Free Software Foundation, Inc. |
7c192733 | 6 | |
93509525 KD |
7 | Written by Cygnus Support. |
8 | ||
9 | This file is part of BFD, the Binary File Descriptor library. | |
10 | ||
11 | This program is free software; you can redistribute it and/or modify | |
12 | it under the terms of the GNU General Public License as published by | |
13 | the Free Software Foundation; either version 2 of the License, or | |
14 | (at your option) any later version. | |
15 | ||
16 | This program is distributed in the hope that it will be useful, | |
17 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | GNU General Public License for more details. | |
20 | ||
21 | You should have received a copy of the GNU General Public License | |
22 | along with this program; if not, write to the Free Software | |
3e110533 | 23 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
93509525 KD |
24 | |
25 | #include "sysdep.h" | |
3db64b00 | 26 | #include <limits.h> |
93509525 KD |
27 | #include "bfd.h" |
28 | #include "libbfd.h" | |
29 | ||
93509525 KD |
30 | #ifndef S_IXUSR |
31 | #define S_IXUSR 0100 /* Execute by owner. */ | |
32 | #endif | |
33 | #ifndef S_IXGRP | |
34 | #define S_IXGRP 0010 /* Execute by group. */ | |
35 | #endif | |
36 | #ifndef S_IXOTH | |
37 | #define S_IXOTH 0001 /* Execute by others. */ | |
38 | #endif | |
39 | ||
7c192733 AC |
40 | file_ptr |
41 | real_ftell (FILE *file) | |
42 | { | |
43 | #if defined (HAVE_FTELLO64) | |
44 | return ftello64 (file); | |
45 | #elif defined (HAVE_FTELLO) | |
46 | return ftello (file); | |
47 | #else | |
48 | return ftell (file); | |
49 | #endif | |
50 | } | |
51 | ||
52 | int | |
53 | real_fseek (FILE *file, file_ptr offset, int whence) | |
54 | { | |
55 | #if defined (HAVE_FSEEKO64) | |
56 | return fseeko64 (file, offset, whence); | |
57 | #elif defined (HAVE_FSEEKO) | |
58 | return fseeko (file, offset, whence); | |
59 | #else | |
60 | return fseek (file, offset, whence); | |
61 | #endif | |
62 | } | |
63 | ||
2e6f4fae DJ |
64 | FILE * |
65 | real_fopen (const char *filename, const char *modes) | |
66 | { | |
67 | #if defined (HAVE_FOPEN64) | |
68 | return fopen64 (filename, modes); | |
69 | #else | |
70 | return fopen (filename, modes); | |
71 | #endif | |
72 | } | |
73 | ||
40838a72 AC |
74 | /* |
75 | INTERNAL_DEFINITION | |
76 | struct bfd_iovec | |
93509525 | 77 | |
40838a72 | 78 | DESCRIPTION |
93509525 | 79 | |
40838a72 AC |
80 | The <<struct bfd_iovec>> contains the internal file I/O class. |
81 | Each <<BFD>> has an instance of this class and all file I/O is | |
82 | routed through it (it is assumed that the instance implements | |
83 | all methods listed below). | |
84 | ||
85 | .struct bfd_iovec | |
86 | .{ | |
87 | . {* To avoid problems with macros, a "b" rather than "f" | |
88 | . prefix is prepended to each method name. *} | |
89 | . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching | |
90 | . bytes starting at PTR. Return the number of bytes actually | |
91 | . transfered (a read past end-of-file returns less than NBYTES), | |
92 | . or -1 (setting <<bfd_error>>) if an error occurs. *} | |
93 | . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes); | |
94 | . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr, | |
95 | . file_ptr nbytes); | |
96 | . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>> | |
97 | . if an error occurs. *} | |
98 | . file_ptr (*btell) (struct bfd *abfd); | |
99 | . {* For the following, on successful completion a value of 0 is returned. | |
100 | . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *} | |
101 | . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence); | |
102 | . int (*bclose) (struct bfd *abfd); | |
103 | . int (*bflush) (struct bfd *abfd); | |
104 | . int (*bstat) (struct bfd *abfd, struct stat *sb); | |
105 | .}; | |
93509525 | 106 | |
40838a72 | 107 | */ |
93509525 | 108 | |
93509525 KD |
109 | |
110 | /* Return value is amount read. */ | |
111 | ||
112 | bfd_size_type | |
c58b9523 | 113 | bfd_bread (void *ptr, bfd_size_type size, bfd *abfd) |
93509525 KD |
114 | { |
115 | size_t nread; | |
116 | ||
1fb41da4 AM |
117 | /* If this is an archive element, don't read past the end of |
118 | this element. */ | |
119 | if (abfd->arelt_data != NULL) | |
120 | { | |
121 | size_t maxbytes = ((struct areltdata *) abfd->arelt_data)->parsed_size; | |
122 | if (size > maxbytes) | |
123 | size = maxbytes; | |
124 | } | |
125 | ||
93509525 KD |
126 | if ((abfd->flags & BFD_IN_MEMORY) != 0) |
127 | { | |
128 | struct bfd_in_memory *bim; | |
129 | bfd_size_type get; | |
130 | ||
c58b9523 | 131 | bim = abfd->iostream; |
93509525 KD |
132 | get = size; |
133 | if (abfd->where + get > bim->size) | |
134 | { | |
135 | if (bim->size < (bfd_size_type) abfd->where) | |
136 | get = 0; | |
137 | else | |
138 | get = bim->size - abfd->where; | |
139 | bfd_set_error (bfd_error_file_truncated); | |
140 | } | |
141 | memcpy (ptr, bim->buffer + abfd->where, (size_t) get); | |
142 | abfd->where += get; | |
143 | return get; | |
144 | } | |
145 | ||
69fd4758 NC |
146 | if (abfd->iovec) |
147 | nread = abfd->iovec->bread (abfd, ptr, size); | |
148 | else | |
149 | nread = 0; | |
93509525 KD |
150 | if (nread != (size_t) -1) |
151 | abfd->where += nread; | |
152 | ||
93509525 KD |
153 | return nread; |
154 | } | |
155 | ||
156 | bfd_size_type | |
c58b9523 | 157 | bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd) |
93509525 KD |
158 | { |
159 | size_t nwrote; | |
160 | ||
161 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
162 | { | |
c58b9523 | 163 | struct bfd_in_memory *bim = abfd->iostream; |
69fd4758 | 164 | |
93509525 KD |
165 | size = (size_t) size; |
166 | if (abfd->where + size > bim->size) | |
167 | { | |
168 | bfd_size_type newsize, oldsize; | |
169 | ||
170 | oldsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
171 | bim->size = abfd->where + size; | |
172 | /* Round up to cut down on memory fragmentation */ | |
173 | newsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
174 | if (newsize > oldsize) | |
175 | { | |
c58b9523 | 176 | bim->buffer = bfd_realloc (bim->buffer, newsize); |
93509525 KD |
177 | if (bim->buffer == 0) |
178 | { | |
179 | bim->size = 0; | |
180 | return 0; | |
181 | } | |
182 | } | |
183 | } | |
184 | memcpy (bim->buffer + abfd->where, ptr, (size_t) size); | |
185 | abfd->where += size; | |
186 | return size; | |
187 | } | |
188 | ||
69fd4758 NC |
189 | if (abfd->iovec) |
190 | nwrote = abfd->iovec->bwrite (abfd, ptr, size); | |
191 | else | |
192 | nwrote = 0; | |
193 | ||
93509525 KD |
194 | if (nwrote != (size_t) -1) |
195 | abfd->where += nwrote; | |
196 | if (nwrote != size) | |
197 | { | |
198 | #ifdef ENOSPC | |
199 | errno = ENOSPC; | |
200 | #endif | |
201 | bfd_set_error (bfd_error_system_call); | |
202 | } | |
203 | return nwrote; | |
204 | } | |
205 | ||
7c192733 | 206 | file_ptr |
c58b9523 | 207 | bfd_tell (bfd *abfd) |
93509525 KD |
208 | { |
209 | file_ptr ptr; | |
210 | ||
211 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
212 | return abfd->where; | |
213 | ||
69fd4758 NC |
214 | if (abfd->iovec) |
215 | { | |
216 | ptr = abfd->iovec->btell (abfd); | |
217 | ||
218 | if (abfd->my_archive) | |
219 | ptr -= abfd->origin; | |
220 | } | |
221 | else | |
222 | ptr = 0; | |
93509525 | 223 | |
93509525 KD |
224 | abfd->where = ptr; |
225 | return ptr; | |
226 | } | |
227 | ||
228 | int | |
c58b9523 | 229 | bfd_flush (bfd *abfd) |
93509525 KD |
230 | { |
231 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
232 | return 0; | |
69fd4758 NC |
233 | |
234 | if (abfd->iovec) | |
235 | return abfd->iovec->bflush (abfd); | |
236 | return 0; | |
93509525 KD |
237 | } |
238 | ||
239 | /* Returns 0 for success, negative value for failure (in which case | |
240 | bfd_get_error can retrieve the error code). */ | |
241 | int | |
c58b9523 | 242 | bfd_stat (bfd *abfd, struct stat *statbuf) |
93509525 | 243 | { |
93509525 KD |
244 | int result; |
245 | ||
246 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
247 | abort (); | |
248 | ||
69fd4758 NC |
249 | if (abfd->iovec) |
250 | result = abfd->iovec->bstat (abfd, statbuf); | |
251 | else | |
252 | result = -1; | |
253 | ||
93509525 KD |
254 | if (result < 0) |
255 | bfd_set_error (bfd_error_system_call); | |
256 | return result; | |
257 | } | |
258 | ||
259 | /* Returns 0 for success, nonzero for failure (in which case bfd_get_error | |
260 | can retrieve the error code). */ | |
261 | ||
262 | int | |
c58b9523 | 263 | bfd_seek (bfd *abfd, file_ptr position, int direction) |
93509525 KD |
264 | { |
265 | int result; | |
7c192733 | 266 | file_ptr file_position; |
93509525 KD |
267 | /* For the time being, a BFD may not seek to it's end. The problem |
268 | is that we don't easily have a way to recognize the end of an | |
269 | element in an archive. */ | |
270 | ||
271 | BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR); | |
272 | ||
273 | if (direction == SEEK_CUR && position == 0) | |
274 | return 0; | |
275 | ||
276 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
277 | { | |
278 | struct bfd_in_memory *bim; | |
279 | ||
c58b9523 | 280 | bim = abfd->iostream; |
93509525 KD |
281 | |
282 | if (direction == SEEK_SET) | |
283 | abfd->where = position; | |
284 | else | |
285 | abfd->where += position; | |
286 | ||
287 | if (abfd->where > bim->size) | |
288 | { | |
289 | if ((abfd->direction == write_direction) || | |
290 | (abfd->direction == both_direction)) | |
291 | { | |
292 | bfd_size_type newsize, oldsize; | |
69fd4758 | 293 | |
93509525 KD |
294 | oldsize = (bim->size + 127) & ~(bfd_size_type) 127; |
295 | bim->size = abfd->where; | |
296 | /* Round up to cut down on memory fragmentation */ | |
297 | newsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
298 | if (newsize > oldsize) | |
299 | { | |
c58b9523 | 300 | bim->buffer = bfd_realloc (bim->buffer, newsize); |
93509525 KD |
301 | if (bim->buffer == 0) |
302 | { | |
303 | bim->size = 0; | |
304 | return -1; | |
305 | } | |
306 | } | |
307 | } | |
308 | else | |
309 | { | |
310 | abfd->where = bim->size; | |
311 | bfd_set_error (bfd_error_file_truncated); | |
312 | return -1; | |
313 | } | |
314 | } | |
315 | return 0; | |
316 | } | |
317 | ||
318 | if (abfd->format != bfd_archive && abfd->my_archive == 0) | |
319 | { | |
93509525 KD |
320 | if (direction == SEEK_SET && (bfd_vma) position == abfd->where) |
321 | return 0; | |
322 | } | |
323 | else | |
324 | { | |
325 | /* We need something smarter to optimize access to archives. | |
326 | Currently, anything inside an archive is read via the file | |
327 | handle for the archive. Which means that a bfd_seek on one | |
328 | component affects the `current position' in the archive, as | |
329 | well as in any other component. | |
330 | ||
331 | It might be sufficient to put a spike through the cache | |
332 | abstraction, and look to the archive for the file position, | |
333 | but I think we should try for something cleaner. | |
334 | ||
335 | In the meantime, no optimization for archives. */ | |
336 | } | |
337 | ||
93509525 KD |
338 | file_position = position; |
339 | if (direction == SEEK_SET && abfd->my_archive != NULL) | |
340 | file_position += abfd->origin; | |
341 | ||
69fd4758 NC |
342 | if (abfd->iovec) |
343 | result = abfd->iovec->bseek (abfd, file_position, direction); | |
344 | else | |
345 | result = -1; | |
346 | ||
93509525 KD |
347 | if (result != 0) |
348 | { | |
349 | int hold_errno = errno; | |
350 | ||
351 | /* Force redetermination of `where' field. */ | |
352 | bfd_tell (abfd); | |
353 | ||
354 | /* An EINVAL error probably means that the file offset was | |
355 | absurd. */ | |
356 | if (hold_errno == EINVAL) | |
357 | bfd_set_error (bfd_error_file_truncated); | |
358 | else | |
359 | { | |
360 | bfd_set_error (bfd_error_system_call); | |
361 | errno = hold_errno; | |
362 | } | |
363 | } | |
364 | else | |
365 | { | |
366 | /* Adjust `where' field. */ | |
367 | if (direction == SEEK_SET) | |
368 | abfd->where = position; | |
369 | else | |
370 | abfd->where += position; | |
371 | } | |
372 | return result; | |
373 | } | |
374 | ||
375 | /* | |
376 | FUNCTION | |
377 | bfd_get_mtime | |
378 | ||
379 | SYNOPSIS | |
c58b9523 | 380 | long bfd_get_mtime (bfd *abfd); |
93509525 KD |
381 | |
382 | DESCRIPTION | |
383 | Return the file modification time (as read from the file system, or | |
384 | from the archive header for archive members). | |
385 | ||
386 | */ | |
387 | ||
388 | long | |
c58b9523 | 389 | bfd_get_mtime (bfd *abfd) |
93509525 | 390 | { |
93509525 KD |
391 | struct stat buf; |
392 | ||
393 | if (abfd->mtime_set) | |
394 | return abfd->mtime; | |
395 | ||
69fd4758 NC |
396 | if (abfd->iovec == NULL) |
397 | return 0; | |
398 | ||
40838a72 | 399 | if (abfd->iovec->bstat (abfd, &buf) != 0) |
93509525 KD |
400 | return 0; |
401 | ||
402 | abfd->mtime = buf.st_mtime; /* Save value in case anyone wants it */ | |
403 | return buf.st_mtime; | |
404 | } | |
405 | ||
406 | /* | |
407 | FUNCTION | |
408 | bfd_get_size | |
409 | ||
410 | SYNOPSIS | |
74633dd0 | 411 | file_ptr bfd_get_size (bfd *abfd); |
93509525 KD |
412 | |
413 | DESCRIPTION | |
414 | Return the file size (as read from file system) for the file | |
415 | associated with BFD @var{abfd}. | |
416 | ||
417 | The initial motivation for, and use of, this routine is not | |
418 | so we can get the exact size of the object the BFD applies to, since | |
419 | that might not be generally possible (archive members for example). | |
420 | It would be ideal if someone could eventually modify | |
421 | it so that such results were guaranteed. | |
422 | ||
423 | Instead, we want to ask questions like "is this NNN byte sized | |
424 | object I'm about to try read from file offset YYY reasonable?" | |
425 | As as example of where we might do this, some object formats | |
426 | use string tables for which the first <<sizeof (long)>> bytes of the | |
427 | table contain the size of the table itself, including the size bytes. | |
428 | If an application tries to read what it thinks is one of these | |
429 | string tables, without some way to validate the size, and for | |
430 | some reason the size is wrong (byte swapping error, wrong location | |
431 | for the string table, etc.), the only clue is likely to be a read | |
432 | error when it tries to read the table, or a "virtual memory | |
433 | exhausted" error when it tries to allocate 15 bazillon bytes | |
434 | of space for the 15 bazillon byte table it is about to read. | |
5c4491d3 | 435 | This function at least allows us to answer the question, "is the |
93509525 KD |
436 | size reasonable?". |
437 | */ | |
438 | ||
74633dd0 | 439 | file_ptr |
c58b9523 | 440 | bfd_get_size (bfd *abfd) |
93509525 | 441 | { |
93509525 KD |
442 | struct stat buf; |
443 | ||
444 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
445 | return ((struct bfd_in_memory *) abfd->iostream)->size; | |
446 | ||
69fd4758 NC |
447 | if (abfd->iovec == NULL) |
448 | return 0; | |
449 | ||
40838a72 | 450 | if (abfd->iovec->bstat (abfd, &buf) != 0) |
93509525 KD |
451 | return 0; |
452 | ||
453 | return buf.st_size; | |
454 | } |