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, | |
4 | 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. | |
5 | ||
93509525 KD |
6 | Written by Cygnus Support. |
7 | ||
8 | This file is part of BFD, the Binary File Descriptor library. | |
9 | ||
10 | This program is free software; you can redistribute it and/or modify | |
11 | it under the terms of the GNU General Public License as published by | |
12 | the Free Software Foundation; either version 2 of the License, or | |
13 | (at your option) any later version. | |
14 | ||
15 | This program is distributed in the hope that it will be useful, | |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | GNU General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU General Public License | |
21 | along with this program; if not, write to the Free Software | |
22 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
23 | ||
24 | #include "sysdep.h" | |
25 | ||
26 | #include "bfd.h" | |
27 | #include "libbfd.h" | |
28 | ||
29 | #include <limits.h> | |
30 | ||
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 | ||
7c192733 AC |
41 | file_ptr |
42 | real_ftell (FILE *file) | |
43 | { | |
44 | #if defined (HAVE_FTELLO64) | |
45 | return ftello64 (file); | |
46 | #elif defined (HAVE_FTELLO) | |
47 | return ftello (file); | |
48 | #else | |
49 | return ftell (file); | |
50 | #endif | |
51 | } | |
52 | ||
53 | int | |
54 | real_fseek (FILE *file, file_ptr offset, int whence) | |
55 | { | |
56 | #if defined (HAVE_FSEEKO64) | |
57 | return fseeko64 (file, offset, whence); | |
58 | #elif defined (HAVE_FSEEKO) | |
59 | return fseeko (file, offset, whence); | |
60 | #else | |
61 | return fseek (file, offset, whence); | |
62 | #endif | |
63 | } | |
64 | ||
40838a72 AC |
65 | /* |
66 | INTERNAL_DEFINITION | |
67 | struct bfd_iovec | |
93509525 | 68 | |
40838a72 | 69 | DESCRIPTION |
93509525 | 70 | |
40838a72 AC |
71 | The <<struct bfd_iovec>> contains the internal file I/O class. |
72 | Each <<BFD>> has an instance of this class and all file I/O is | |
73 | routed through it (it is assumed that the instance implements | |
74 | all methods listed below). | |
75 | ||
76 | .struct bfd_iovec | |
77 | .{ | |
78 | . {* To avoid problems with macros, a "b" rather than "f" | |
79 | . prefix is prepended to each method name. *} | |
80 | . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching | |
81 | . bytes starting at PTR. Return the number of bytes actually | |
82 | . transfered (a read past end-of-file returns less than NBYTES), | |
83 | . or -1 (setting <<bfd_error>>) if an error occurs. *} | |
84 | . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes); | |
85 | . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr, | |
86 | . file_ptr nbytes); | |
87 | . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>> | |
88 | . if an error occurs. *} | |
89 | . file_ptr (*btell) (struct bfd *abfd); | |
90 | . {* For the following, on successful completion a value of 0 is returned. | |
91 | . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *} | |
92 | . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence); | |
93 | . int (*bclose) (struct bfd *abfd); | |
94 | . int (*bflush) (struct bfd *abfd); | |
95 | . int (*bstat) (struct bfd *abfd, struct stat *sb); | |
96 | .}; | |
93509525 | 97 | |
40838a72 | 98 | */ |
93509525 | 99 | |
93509525 KD |
100 | |
101 | /* Return value is amount read. */ | |
102 | ||
103 | bfd_size_type | |
c58b9523 | 104 | bfd_bread (void *ptr, bfd_size_type size, bfd *abfd) |
93509525 KD |
105 | { |
106 | size_t nread; | |
107 | ||
108 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
109 | { | |
110 | struct bfd_in_memory *bim; | |
111 | bfd_size_type get; | |
112 | ||
c58b9523 | 113 | bim = abfd->iostream; |
93509525 KD |
114 | get = size; |
115 | if (abfd->where + get > bim->size) | |
116 | { | |
117 | if (bim->size < (bfd_size_type) abfd->where) | |
118 | get = 0; | |
119 | else | |
120 | get = bim->size - abfd->where; | |
121 | bfd_set_error (bfd_error_file_truncated); | |
122 | } | |
123 | memcpy (ptr, bim->buffer + abfd->where, (size_t) get); | |
124 | abfd->where += get; | |
125 | return get; | |
126 | } | |
127 | ||
40838a72 | 128 | nread = abfd->iovec->bread (abfd, ptr, size); |
93509525 KD |
129 | if (nread != (size_t) -1) |
130 | abfd->where += nread; | |
131 | ||
93509525 KD |
132 | return nread; |
133 | } | |
134 | ||
135 | bfd_size_type | |
c58b9523 | 136 | bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd) |
93509525 KD |
137 | { |
138 | size_t nwrote; | |
139 | ||
140 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
141 | { | |
c58b9523 | 142 | struct bfd_in_memory *bim = abfd->iostream; |
93509525 KD |
143 | size = (size_t) size; |
144 | if (abfd->where + size > bim->size) | |
145 | { | |
146 | bfd_size_type newsize, oldsize; | |
147 | ||
148 | oldsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
149 | bim->size = abfd->where + size; | |
150 | /* Round up to cut down on memory fragmentation */ | |
151 | newsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
152 | if (newsize > oldsize) | |
153 | { | |
c58b9523 | 154 | bim->buffer = bfd_realloc (bim->buffer, newsize); |
93509525 KD |
155 | if (bim->buffer == 0) |
156 | { | |
157 | bim->size = 0; | |
158 | return 0; | |
159 | } | |
160 | } | |
161 | } | |
162 | memcpy (bim->buffer + abfd->where, ptr, (size_t) size); | |
163 | abfd->where += size; | |
164 | return size; | |
165 | } | |
166 | ||
40838a72 | 167 | nwrote = abfd->iovec->bwrite (abfd, ptr, size); |
93509525 KD |
168 | if (nwrote != (size_t) -1) |
169 | abfd->where += nwrote; | |
170 | if (nwrote != size) | |
171 | { | |
172 | #ifdef ENOSPC | |
173 | errno = ENOSPC; | |
174 | #endif | |
175 | bfd_set_error (bfd_error_system_call); | |
176 | } | |
177 | return nwrote; | |
178 | } | |
179 | ||
7c192733 | 180 | file_ptr |
c58b9523 | 181 | bfd_tell (bfd *abfd) |
93509525 KD |
182 | { |
183 | file_ptr ptr; | |
184 | ||
185 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
186 | return abfd->where; | |
187 | ||
40838a72 | 188 | ptr = abfd->iovec->btell (abfd); |
93509525 KD |
189 | |
190 | if (abfd->my_archive) | |
191 | ptr -= abfd->origin; | |
192 | abfd->where = ptr; | |
193 | return ptr; | |
194 | } | |
195 | ||
196 | int | |
c58b9523 | 197 | bfd_flush (bfd *abfd) |
93509525 KD |
198 | { |
199 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
200 | return 0; | |
40838a72 | 201 | return abfd->iovec->bflush (abfd); |
93509525 KD |
202 | } |
203 | ||
204 | /* Returns 0 for success, negative value for failure (in which case | |
205 | bfd_get_error can retrieve the error code). */ | |
206 | int | |
c58b9523 | 207 | bfd_stat (bfd *abfd, struct stat *statbuf) |
93509525 | 208 | { |
93509525 KD |
209 | int result; |
210 | ||
211 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
212 | abort (); | |
213 | ||
40838a72 | 214 | result = abfd->iovec->bstat (abfd, statbuf); |
93509525 KD |
215 | if (result < 0) |
216 | bfd_set_error (bfd_error_system_call); | |
217 | return result; | |
218 | } | |
219 | ||
220 | /* Returns 0 for success, nonzero for failure (in which case bfd_get_error | |
221 | can retrieve the error code). */ | |
222 | ||
223 | int | |
c58b9523 | 224 | bfd_seek (bfd *abfd, file_ptr position, int direction) |
93509525 KD |
225 | { |
226 | int result; | |
7c192733 | 227 | file_ptr file_position; |
93509525 KD |
228 | /* For the time being, a BFD may not seek to it's end. The problem |
229 | is that we don't easily have a way to recognize the end of an | |
230 | element in an archive. */ | |
231 | ||
232 | BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR); | |
233 | ||
234 | if (direction == SEEK_CUR && position == 0) | |
235 | return 0; | |
236 | ||
237 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
238 | { | |
239 | struct bfd_in_memory *bim; | |
240 | ||
c58b9523 | 241 | bim = abfd->iostream; |
93509525 KD |
242 | |
243 | if (direction == SEEK_SET) | |
244 | abfd->where = position; | |
245 | else | |
246 | abfd->where += position; | |
247 | ||
248 | if (abfd->where > bim->size) | |
249 | { | |
250 | if ((abfd->direction == write_direction) || | |
251 | (abfd->direction == both_direction)) | |
252 | { | |
253 | bfd_size_type newsize, oldsize; | |
254 | oldsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
255 | bim->size = abfd->where; | |
256 | /* Round up to cut down on memory fragmentation */ | |
257 | newsize = (bim->size + 127) & ~(bfd_size_type) 127; | |
258 | if (newsize > oldsize) | |
259 | { | |
c58b9523 | 260 | bim->buffer = bfd_realloc (bim->buffer, newsize); |
93509525 KD |
261 | if (bim->buffer == 0) |
262 | { | |
263 | bim->size = 0; | |
264 | return -1; | |
265 | } | |
266 | } | |
267 | } | |
268 | else | |
269 | { | |
270 | abfd->where = bim->size; | |
271 | bfd_set_error (bfd_error_file_truncated); | |
272 | return -1; | |
273 | } | |
274 | } | |
275 | return 0; | |
276 | } | |
277 | ||
278 | if (abfd->format != bfd_archive && abfd->my_archive == 0) | |
279 | { | |
280 | #if 0 | |
281 | /* Explanation for this code: I'm only about 95+% sure that the above | |
282 | conditions are sufficient and that all i/o calls are properly | |
283 | adjusting the `where' field. So this is sort of an `assert' | |
284 | that the `where' field is correct. If we can go a while without | |
285 | tripping the abort, we can probably safely disable this code, | |
286 | so that the real optimizations happen. */ | |
287 | file_ptr where_am_i_now; | |
7c192733 | 288 | where_am_i_now = real_ftell (bfd_cache_lookup (abfd)); |
93509525 KD |
289 | if (abfd->my_archive) |
290 | where_am_i_now -= abfd->origin; | |
291 | if (where_am_i_now != abfd->where) | |
292 | abort (); | |
293 | #endif | |
294 | if (direction == SEEK_SET && (bfd_vma) position == abfd->where) | |
295 | return 0; | |
296 | } | |
297 | else | |
298 | { | |
299 | /* We need something smarter to optimize access to archives. | |
300 | Currently, anything inside an archive is read via the file | |
301 | handle for the archive. Which means that a bfd_seek on one | |
302 | component affects the `current position' in the archive, as | |
303 | well as in any other component. | |
304 | ||
305 | It might be sufficient to put a spike through the cache | |
306 | abstraction, and look to the archive for the file position, | |
307 | but I think we should try for something cleaner. | |
308 | ||
309 | In the meantime, no optimization for archives. */ | |
310 | } | |
311 | ||
93509525 KD |
312 | file_position = position; |
313 | if (direction == SEEK_SET && abfd->my_archive != NULL) | |
314 | file_position += abfd->origin; | |
315 | ||
40838a72 | 316 | result = abfd->iovec->bseek (abfd, file_position, direction); |
93509525 KD |
317 | if (result != 0) |
318 | { | |
319 | int hold_errno = errno; | |
320 | ||
321 | /* Force redetermination of `where' field. */ | |
322 | bfd_tell (abfd); | |
323 | ||
324 | /* An EINVAL error probably means that the file offset was | |
325 | absurd. */ | |
326 | if (hold_errno == EINVAL) | |
327 | bfd_set_error (bfd_error_file_truncated); | |
328 | else | |
329 | { | |
330 | bfd_set_error (bfd_error_system_call); | |
331 | errno = hold_errno; | |
332 | } | |
333 | } | |
334 | else | |
335 | { | |
336 | /* Adjust `where' field. */ | |
337 | if (direction == SEEK_SET) | |
338 | abfd->where = position; | |
339 | else | |
340 | abfd->where += position; | |
341 | } | |
342 | return result; | |
343 | } | |
344 | ||
345 | /* | |
346 | FUNCTION | |
347 | bfd_get_mtime | |
348 | ||
349 | SYNOPSIS | |
c58b9523 | 350 | long bfd_get_mtime (bfd *abfd); |
93509525 KD |
351 | |
352 | DESCRIPTION | |
353 | Return the file modification time (as read from the file system, or | |
354 | from the archive header for archive members). | |
355 | ||
356 | */ | |
357 | ||
358 | long | |
c58b9523 | 359 | bfd_get_mtime (bfd *abfd) |
93509525 | 360 | { |
93509525 KD |
361 | struct stat buf; |
362 | ||
363 | if (abfd->mtime_set) | |
364 | return abfd->mtime; | |
365 | ||
40838a72 | 366 | if (abfd->iovec->bstat (abfd, &buf) != 0) |
93509525 KD |
367 | return 0; |
368 | ||
369 | abfd->mtime = buf.st_mtime; /* Save value in case anyone wants it */ | |
370 | return buf.st_mtime; | |
371 | } | |
372 | ||
373 | /* | |
374 | FUNCTION | |
375 | bfd_get_size | |
376 | ||
377 | SYNOPSIS | |
c58b9523 | 378 | long bfd_get_size (bfd *abfd); |
93509525 KD |
379 | |
380 | DESCRIPTION | |
381 | Return the file size (as read from file system) for the file | |
382 | associated with BFD @var{abfd}. | |
383 | ||
384 | The initial motivation for, and use of, this routine is not | |
385 | so we can get the exact size of the object the BFD applies to, since | |
386 | that might not be generally possible (archive members for example). | |
387 | It would be ideal if someone could eventually modify | |
388 | it so that such results were guaranteed. | |
389 | ||
390 | Instead, we want to ask questions like "is this NNN byte sized | |
391 | object I'm about to try read from file offset YYY reasonable?" | |
392 | As as example of where we might do this, some object formats | |
393 | use string tables for which the first <<sizeof (long)>> bytes of the | |
394 | table contain the size of the table itself, including the size bytes. | |
395 | If an application tries to read what it thinks is one of these | |
396 | string tables, without some way to validate the size, and for | |
397 | some reason the size is wrong (byte swapping error, wrong location | |
398 | for the string table, etc.), the only clue is likely to be a read | |
399 | error when it tries to read the table, or a "virtual memory | |
400 | exhausted" error when it tries to allocate 15 bazillon bytes | |
401 | of space for the 15 bazillon byte table it is about to read. | |
5c4491d3 | 402 | This function at least allows us to answer the question, "is the |
93509525 KD |
403 | size reasonable?". |
404 | */ | |
405 | ||
406 | long | |
c58b9523 | 407 | bfd_get_size (bfd *abfd) |
93509525 | 408 | { |
93509525 KD |
409 | struct stat buf; |
410 | ||
411 | if ((abfd->flags & BFD_IN_MEMORY) != 0) | |
412 | return ((struct bfd_in_memory *) abfd->iostream)->size; | |
413 | ||
40838a72 | 414 | if (abfd->iovec->bstat (abfd, &buf) != 0) |
93509525 KD |
415 | return 0; |
416 | ||
417 | return buf.st_size; | |
418 | } |