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