Commit | Line | Data |
---|---|---|
93509525 | 1 | /* Low-level I/O routines for BFDs. |
7c192733 AC |
2 | |
3 | Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
515ef31d | 4 | 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 |
9553c638 | 5 | Free Software Foundation, Inc. |
7c192733 | 6 | |
93509525 KD |
7 | Written by Cygnus Support. |
8 | ||
cd123cb7 | 9 | This file is part of BFD, the Binary File Descriptor library. |
93509525 | 10 | |
cd123cb7 NC |
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 3 of the License, or | |
14 | (at your option) any later version. | |
93509525 | 15 | |
cd123cb7 NC |
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. | |
93509525 | 20 | |
cd123cb7 NC |
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 | |
23 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
24 | MA 02110-1301, USA. */ | |
93509525 KD |
25 | |
26 | #include "sysdep.h" | |
3db64b00 | 27 | #include <limits.h> |
93509525 KD |
28 | #include "bfd.h" |
29 | #include "libbfd.h" | |
30 | ||
93509525 KD |
31 | #ifndef S_IXUSR |
32 | #define S_IXUSR 0100 /* Execute by owner. */ | |
33 | #endif | |
34 | #ifndef S_IXGRP | |
35 | #define S_IXGRP 0010 /* Execute by group. */ | |
36 | #endif | |
37 | #ifndef S_IXOTH | |
38 | #define S_IXOTH 0001 /* Execute by others. */ | |
39 | #endif | |
40 | ||
428b207a TT |
41 | #ifndef FD_CLOEXEC |
42 | #define FD_CLOEXEC 1 | |
43 | #endif | |
44 | ||
7c192733 AC |
45 | file_ptr |
46 | real_ftell (FILE *file) | |
47 | { | |
48 | #if defined (HAVE_FTELLO64) | |
49 | return ftello64 (file); | |
50 | #elif defined (HAVE_FTELLO) | |
51 | return ftello (file); | |
52 | #else | |
53 | return ftell (file); | |
54 | #endif | |
55 | } | |
56 | ||
57 | int | |
58 | real_fseek (FILE *file, file_ptr offset, int whence) | |
59 | { | |
60 | #if defined (HAVE_FSEEKO64) | |
61 | return fseeko64 (file, offset, whence); | |
62 | #elif defined (HAVE_FSEEKO) | |
63 | return fseeko (file, offset, whence); | |
64 | #else | |
65 | return fseek (file, offset, whence); | |
66 | #endif | |
67 | } | |
68 | ||
428b207a TT |
69 | /* Mark FILE as close-on-exec. Return FILE. FILE may be NULL, in |
70 | which case nothing is done. */ | |
71 | static FILE * | |
72 | close_on_exec (FILE *file) | |
73 | { | |
74 | #if defined (HAVE_FILENO) && defined (F_GETFD) | |
75 | if (file) | |
76 | { | |
77 | int fd = fileno (file); | |
78 | int old = fcntl (fd, F_GETFD, 0); | |
79 | if (old >= 0) | |
80 | fcntl (fd, F_SETFD, old | FD_CLOEXEC); | |
81 | } | |
82 | #endif | |
83 | return file; | |
84 | } | |
85 | ||
2e6f4fae DJ |
86 | FILE * |
87 | real_fopen (const char *filename, const char *modes) | |
88 | { | |
89 | #if defined (HAVE_FOPEN64) | |
428b207a | 90 | return close_on_exec (fopen64 (filename, modes)); |
2e6f4fae | 91 | #else |
428b207a | 92 | return close_on_exec (fopen (filename, modes)); |
2e6f4fae DJ |
93 | #endif |
94 | } | |
95 | ||
40838a72 AC |
96 | /* |
97 | INTERNAL_DEFINITION | |
98 | struct bfd_iovec | |
93509525 | 99 | |
40838a72 | 100 | DESCRIPTION |
93509525 | 101 | |
40838a72 AC |
102 | The <<struct bfd_iovec>> contains the internal file I/O class. |
103 | Each <<BFD>> has an instance of this class and all file I/O is | |
104 | routed through it (it is assumed that the instance implements | |
105 | all methods listed below). | |
106 | ||
107 | .struct bfd_iovec | |
108 | .{ | |
109 | . {* To avoid problems with macros, a "b" rather than "f" | |
110 | . prefix is prepended to each method name. *} | |
111 | . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching | |
112 | . bytes starting at PTR. Return the number of bytes actually | |
113 | . transfered (a read past end-of-file returns less than NBYTES), | |
114 | . or -1 (setting <<bfd_error>>) if an error occurs. *} | |
115 | . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes); | |
116 | . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr, | |
117 | . file_ptr nbytes); | |
118 | . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>> | |
119 | . if an error occurs. *} | |
120 | . file_ptr (*btell) (struct bfd *abfd); | |
121 | . {* For the following, on successful completion a value of 0 is returned. | |
122 | . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *} | |
123 | . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence); | |
124 | . int (*bclose) (struct bfd *abfd); | |
125 | . int (*bflush) (struct bfd *abfd); | |
126 | . int (*bstat) (struct bfd *abfd, struct stat *sb); | |
127 | .}; | |
93509525 | 128 | |
40838a72 | 129 | */ |
93509525 | 130 | |
93509525 KD |
131 | |
132 | /* Return value is amount read. */ | |
133 | ||
134 | bfd_size_type | |
c58b9523 | 135 | bfd_bread (void *ptr, bfd_size_type size, bfd *abfd) |
93509525 KD |
136 | { |
137 | size_t nread; | |
138 | ||
1fb41da4 AM |
139 | /* If this is an archive element, don't read past the end of |
140 | this element. */ | |
141 | if (abfd->arelt_data != NULL) | |
142 | { | |
143 | size_t maxbytes = ((struct areltdata *) abfd->arelt_data)->parsed_size; | |
144 | if (size > maxbytes) | |
145 | size = maxbytes; | |
146 | } | |
147 | ||
93509525 KD |
148 | if ((abfd->flags & BFD_IN_MEMORY) != 0) |
149 | { | |
150 | struct bfd_in_memory *bim; | |
151 | bfd_size_type get; | |
152 | ||
c58b9523 | 153 | bim = abfd->iostream; |
93509525 KD |
154 | get = size; |
155 | if (abfd->where + get > bim->size) | |
156 | { | |
157 | if (bim->size < (bfd_size_type) abfd->where) | |
158 | get = 0; | |
159 | else | |
160 | get = bim->size - abfd->where; | |
161 | bfd_set_error (bfd_error_file_truncated); | |
162 | } | |
163 | memcpy (ptr, bim->buffer + abfd->where, (size_t) get); | |
164 | abfd->where += get; | |
165 | return get; | |
166 | } | |
167 | ||
69fd4758 NC |
168 | if (abfd->iovec) |
169 | nread = abfd->iovec->bread (abfd, ptr, size); | |
170 | else | |
171 | nread = 0; | |
93509525 KD |
172 | if (nread != (size_t) -1) |
173 | abfd->where += nread; | |
174 | ||
93509525 KD |
175 | return nread; |
176 | } | |
177 | ||
178 | bfd_size_type | |
c58b9523 | 179 | bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd) |
93509525 KD |
180 | { |
181 | size_t nwrote; | |
182 | ||
183 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
184 | { | |
c58b9523 | 185 | struct bfd_in_memory *bim = abfd->iostream; |
69fd4758 | 186 | |
93509525 KD |
187 | size = (size_t) size; |
188 | if (abfd->where + size > bim->size) | |
189 | { | |
190 | bfd_size_type newsize, oldsize; | |
191 | ||
192 | oldsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
193 | bim->size = abfd->where + size; | |
194 | /* Round up to cut down on memory fragmentation */ | |
195 | newsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
196 | if (newsize > oldsize) | |
197 | { | |
515ef31d NC |
198 | bim->buffer = bfd_realloc_or_free (bim->buffer, newsize); |
199 | if (bim->buffer == NULL) | |
93509525 KD |
200 | { |
201 | bim->size = 0; | |
202 | return 0; | |
203 | } | |
204 | } | |
205 | } | |
206 | memcpy (bim->buffer + abfd->where, ptr, (size_t) size); | |
207 | abfd->where += size; | |
208 | return size; | |
209 | } | |
210 | ||
69fd4758 NC |
211 | if (abfd->iovec) |
212 | nwrote = abfd->iovec->bwrite (abfd, ptr, size); | |
213 | else | |
214 | nwrote = 0; | |
215 | ||
93509525 KD |
216 | if (nwrote != (size_t) -1) |
217 | abfd->where += nwrote; | |
218 | if (nwrote != size) | |
219 | { | |
220 | #ifdef ENOSPC | |
221 | errno = ENOSPC; | |
222 | #endif | |
223 | bfd_set_error (bfd_error_system_call); | |
224 | } | |
225 | return nwrote; | |
226 | } | |
227 | ||
7c192733 | 228 | file_ptr |
c58b9523 | 229 | bfd_tell (bfd *abfd) |
93509525 KD |
230 | { |
231 | file_ptr ptr; | |
232 | ||
233 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
234 | return abfd->where; | |
235 | ||
69fd4758 NC |
236 | if (abfd->iovec) |
237 | { | |
238 | ptr = abfd->iovec->btell (abfd); | |
239 | ||
240 | if (abfd->my_archive) | |
241 | ptr -= abfd->origin; | |
242 | } | |
243 | else | |
244 | ptr = 0; | |
93509525 | 245 | |
93509525 KD |
246 | abfd->where = ptr; |
247 | return ptr; | |
248 | } | |
249 | ||
250 | int | |
c58b9523 | 251 | bfd_flush (bfd *abfd) |
93509525 KD |
252 | { |
253 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
254 | return 0; | |
69fd4758 NC |
255 | |
256 | if (abfd->iovec) | |
257 | return abfd->iovec->bflush (abfd); | |
258 | return 0; | |
93509525 KD |
259 | } |
260 | ||
261 | /* Returns 0 for success, negative value for failure (in which case | |
262 | bfd_get_error can retrieve the error code). */ | |
263 | int | |
c58b9523 | 264 | bfd_stat (bfd *abfd, struct stat *statbuf) |
93509525 | 265 | { |
93509525 KD |
266 | int result; |
267 | ||
268 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
269 | abort (); | |
270 | ||
69fd4758 NC |
271 | if (abfd->iovec) |
272 | result = abfd->iovec->bstat (abfd, statbuf); | |
273 | else | |
274 | result = -1; | |
275 | ||
93509525 KD |
276 | if (result < 0) |
277 | bfd_set_error (bfd_error_system_call); | |
278 | return result; | |
279 | } | |
280 | ||
281 | /* Returns 0 for success, nonzero for failure (in which case bfd_get_error | |
282 | can retrieve the error code). */ | |
283 | ||
284 | int | |
c58b9523 | 285 | bfd_seek (bfd *abfd, file_ptr position, int direction) |
93509525 KD |
286 | { |
287 | int result; | |
7c192733 | 288 | file_ptr file_position; |
93509525 KD |
289 | /* For the time being, a BFD may not seek to it's end. The problem |
290 | is that we don't easily have a way to recognize the end of an | |
291 | element in an archive. */ | |
292 | ||
293 | BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR); | |
294 | ||
295 | if (direction == SEEK_CUR && position == 0) | |
296 | return 0; | |
297 | ||
298 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
299 | { | |
300 | struct bfd_in_memory *bim; | |
301 | ||
c58b9523 | 302 | bim = abfd->iostream; |
93509525 KD |
303 | |
304 | if (direction == SEEK_SET) | |
305 | abfd->where = position; | |
306 | else | |
307 | abfd->where += position; | |
308 | ||
309 | if (abfd->where > bim->size) | |
310 | { | |
311 | if ((abfd->direction == write_direction) || | |
312 | (abfd->direction == both_direction)) | |
313 | { | |
314 | bfd_size_type newsize, oldsize; | |
69fd4758 | 315 | |
93509525 KD |
316 | oldsize = (bim->size + 127) & ~(bfd_size_type) 127; |
317 | bim->size = abfd->where; | |
318 | /* Round up to cut down on memory fragmentation */ | |
319 | newsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
320 | if (newsize > oldsize) | |
321 | { | |
515ef31d NC |
322 | bim->buffer = bfd_realloc_or_free (bim->buffer, newsize); |
323 | if (bim->buffer == NULL) | |
93509525 KD |
324 | { |
325 | bim->size = 0; | |
326 | return -1; | |
327 | } | |
328 | } | |
329 | } | |
330 | else | |
331 | { | |
332 | abfd->where = bim->size; | |
333 | bfd_set_error (bfd_error_file_truncated); | |
334 | return -1; | |
335 | } | |
336 | } | |
337 | return 0; | |
338 | } | |
339 | ||
340 | if (abfd->format != bfd_archive && abfd->my_archive == 0) | |
341 | { | |
93509525 KD |
342 | if (direction == SEEK_SET && (bfd_vma) position == abfd->where) |
343 | return 0; | |
344 | } | |
345 | else | |
346 | { | |
347 | /* We need something smarter to optimize access to archives. | |
348 | Currently, anything inside an archive is read via the file | |
349 | handle for the archive. Which means that a bfd_seek on one | |
350 | component affects the `current position' in the archive, as | |
351 | well as in any other component. | |
352 | ||
353 | It might be sufficient to put a spike through the cache | |
354 | abstraction, and look to the archive for the file position, | |
355 | but I think we should try for something cleaner. | |
356 | ||
357 | In the meantime, no optimization for archives. */ | |
358 | } | |
359 | ||
93509525 KD |
360 | file_position = position; |
361 | if (direction == SEEK_SET && abfd->my_archive != NULL) | |
362 | file_position += abfd->origin; | |
363 | ||
69fd4758 NC |
364 | if (abfd->iovec) |
365 | result = abfd->iovec->bseek (abfd, file_position, direction); | |
366 | else | |
367 | result = -1; | |
368 | ||
93509525 KD |
369 | if (result != 0) |
370 | { | |
371 | int hold_errno = errno; | |
372 | ||
373 | /* Force redetermination of `where' field. */ | |
374 | bfd_tell (abfd); | |
375 | ||
376 | /* An EINVAL error probably means that the file offset was | |
377 | absurd. */ | |
378 | if (hold_errno == EINVAL) | |
379 | bfd_set_error (bfd_error_file_truncated); | |
380 | else | |
381 | { | |
382 | bfd_set_error (bfd_error_system_call); | |
383 | errno = hold_errno; | |
384 | } | |
385 | } | |
386 | else | |
387 | { | |
388 | /* Adjust `where' field. */ | |
389 | if (direction == SEEK_SET) | |
390 | abfd->where = position; | |
391 | else | |
392 | abfd->where += position; | |
393 | } | |
394 | return result; | |
395 | } | |
396 | ||
397 | /* | |
398 | FUNCTION | |
399 | bfd_get_mtime | |
400 | ||
401 | SYNOPSIS | |
c58b9523 | 402 | long bfd_get_mtime (bfd *abfd); |
93509525 KD |
403 | |
404 | DESCRIPTION | |
405 | Return the file modification time (as read from the file system, or | |
406 | from the archive header for archive members). | |
407 | ||
408 | */ | |
409 | ||
410 | long | |
c58b9523 | 411 | bfd_get_mtime (bfd *abfd) |
93509525 | 412 | { |
93509525 KD |
413 | struct stat buf; |
414 | ||
415 | if (abfd->mtime_set) | |
416 | return abfd->mtime; | |
417 | ||
69fd4758 NC |
418 | if (abfd->iovec == NULL) |
419 | return 0; | |
420 | ||
40838a72 | 421 | if (abfd->iovec->bstat (abfd, &buf) != 0) |
93509525 KD |
422 | return 0; |
423 | ||
424 | abfd->mtime = buf.st_mtime; /* Save value in case anyone wants it */ | |
425 | return buf.st_mtime; | |
426 | } | |
427 | ||
428 | /* | |
429 | FUNCTION | |
430 | bfd_get_size | |
431 | ||
432 | SYNOPSIS | |
74633dd0 | 433 | file_ptr bfd_get_size (bfd *abfd); |
93509525 KD |
434 | |
435 | DESCRIPTION | |
436 | Return the file size (as read from file system) for the file | |
437 | associated with BFD @var{abfd}. | |
438 | ||
439 | The initial motivation for, and use of, this routine is not | |
440 | so we can get the exact size of the object the BFD applies to, since | |
441 | that might not be generally possible (archive members for example). | |
442 | It would be ideal if someone could eventually modify | |
443 | it so that such results were guaranteed. | |
444 | ||
445 | Instead, we want to ask questions like "is this NNN byte sized | |
446 | object I'm about to try read from file offset YYY reasonable?" | |
447 | As as example of where we might do this, some object formats | |
448 | use string tables for which the first <<sizeof (long)>> bytes of the | |
449 | table contain the size of the table itself, including the size bytes. | |
450 | If an application tries to read what it thinks is one of these | |
451 | string tables, without some way to validate the size, and for | |
452 | some reason the size is wrong (byte swapping error, wrong location | |
453 | for the string table, etc.), the only clue is likely to be a read | |
454 | error when it tries to read the table, or a "virtual memory | |
455 | exhausted" error when it tries to allocate 15 bazillon bytes | |
456 | of space for the 15 bazillon byte table it is about to read. | |
5c4491d3 | 457 | This function at least allows us to answer the question, "is the |
93509525 KD |
458 | size reasonable?". |
459 | */ | |
460 | ||
74633dd0 | 461 | file_ptr |
c58b9523 | 462 | bfd_get_size (bfd *abfd) |
93509525 | 463 | { |
93509525 KD |
464 | struct stat buf; |
465 | ||
466 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
467 | return ((struct bfd_in_memory *) abfd->iostream)->size; | |
468 | ||
69fd4758 NC |
469 | if (abfd->iovec == NULL) |
470 | return 0; | |
471 | ||
40838a72 | 472 | if (abfd->iovec->bstat (abfd, &buf) != 0) |
93509525 KD |
473 | return 0; |
474 | ||
475 | return buf.st_size; | |
476 | } |