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[binutils-gdb.git] / bfd / bfdio.c
1 /* Low-level I/O routines for BFDs.
2
3 Copyright (C) 1990-2022 Free Software Foundation, Inc.
4
5 Written by Cygnus Support.
6
7 This file is part of BFD, the Binary File Descriptor library.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 MA 02110-1301, USA. */
23
24 #include "sysdep.h"
25 #include <limits.h>
26 #include "bfd.h"
27 #include "libbfd.h"
28 #include "aout/ar.h"
29 #if defined (_WIN32)
30 #include <windows.h>
31 #endif
32
33 #ifndef S_IXUSR
34 #define S_IXUSR 0100 /* Execute by owner. */
35 #endif
36 #ifndef S_IXGRP
37 #define S_IXGRP 0010 /* Execute by group. */
38 #endif
39 #ifndef S_IXOTH
40 #define S_IXOTH 0001 /* Execute by others. */
41 #endif
42
43 #ifndef FD_CLOEXEC
44 #define FD_CLOEXEC 1
45 #endif
46
47 file_ptr
48 _bfd_real_ftell (FILE *file)
49 {
50 #if defined (HAVE_FTELLO64)
51 return ftello64 (file);
52 #elif defined (HAVE_FTELLO)
53 return ftello (file);
54 #else
55 return ftell (file);
56 #endif
57 }
58
59 int
60 _bfd_real_fseek (FILE *file, file_ptr offset, int whence)
61 {
62 #if defined (HAVE_FSEEKO64)
63 return fseeko64 (file, offset, whence);
64 #elif defined (HAVE_FSEEKO)
65 return fseeko (file, offset, whence);
66 #else
67 return fseek (file, offset, whence);
68 #endif
69 }
70
71 /* Mark FILE as close-on-exec. Return FILE. FILE may be NULL, in
72 which case nothing is done. */
73 static FILE *
74 close_on_exec (FILE *file)
75 {
76 #if defined (HAVE_FILENO) && defined (F_GETFD)
77 if (file)
78 {
79 int fd = fileno (file);
80 int old = fcntl (fd, F_GETFD, 0);
81 if (old >= 0)
82 fcntl (fd, F_SETFD, old | FD_CLOEXEC);
83 }
84 #endif
85 return file;
86 }
87
88 FILE *
89 _bfd_real_fopen (const char *filename, const char *modes)
90 {
91 #ifdef VMS
92 char *vms_attr;
93
94 /* On VMS, fopen allows file attributes as optional arguments.
95 We need to use them but we'd better to use the common prototype.
96 In fopen-vms.h, they are separated from the mode with a comma.
97 Split here. */
98 vms_attr = strchr (modes, ',');
99 if (vms_attr != NULL)
100 {
101 /* Attributes found. Split. */
102 size_t modes_len = strlen (modes) + 1;
103 char attrs[modes_len + 1];
104 char *at[3];
105 int i;
106
107 memcpy (attrs, modes, modes_len);
108 at[0] = attrs;
109 for (i = 0; i < 2; i++)
110 {
111 at[i + 1] = strchr (at[i], ',');
112 BFD_ASSERT (at[i + 1] != NULL);
113 *(at[i + 1]++) = 0; /* Replace ',' with a nul, and skip it. */
114 }
115 return close_on_exec (fopen (filename, at[0], at[1], at[2]));
116 }
117
118 #elif defined (_WIN32)
119 /* PR 25713: Handle extra long path names possibly containing '..' and '.'. */
120 wchar_t ** lpFilePart = {NULL};
121 const wchar_t prefix[] = L"\\\\?\\";
122 const size_t partPathLen = strlen (filename) + 1;
123
124 /* Converting the partial path from ascii to unicode.
125 1) Get the length: Calling with lpWideCharStr set to null returns the length.
126 2) Convert the string: Calling with cbMultiByte set to -1 includes the terminating null. */
127 size_t partPathWSize = MultiByteToWideChar (CP_UTF8, 0, filename, -1, NULL, 0);
128 wchar_t * partPath = calloc (partPathWSize, sizeof(wchar_t));
129 size_t ix;
130
131 MultiByteToWideChar (CP_UTF8, 0, filename, -1, partPath, partPathWSize);
132
133 /* Convert any UNIX style path separators into the DOS i.e. backslash separator. */
134 for (ix = 0; ix < partPathLen; ix++)
135 if (IS_UNIX_DIR_SEPARATOR(filename[ix]))
136 partPath[ix] = '\\';
137
138 /* Getting the full path from the provided partial path.
139 1) Get the length.
140 2) Resolve the path. */
141 long fullPathWSize = GetFullPathNameW (partPath, 0, NULL, lpFilePart);
142 wchar_t * fullPath = calloc (fullPathWSize + sizeof(prefix) + 1, sizeof(wchar_t));
143
144 wcscpy (fullPath, prefix);
145
146 int prefixLen = sizeof(prefix) / sizeof(wchar_t);
147 wchar_t * fullPathOffset = fullPath + prefixLen - 1;
148
149 GetFullPathNameW (partPath, fullPathWSize, fullPathOffset, lpFilePart);
150 free (partPath);
151
152 /* It is non-standard for modes to exceed 16 characters. */
153 wchar_t modesW[16];
154
155 MultiByteToWideChar (CP_UTF8, 0, modes, -1, modesW, sizeof(modesW));
156
157 FILE * file = _wfopen (fullPath, modesW);
158 free (fullPath);
159
160 return close_on_exec (file);
161
162 #elif defined (HAVE_FOPEN64)
163 return close_on_exec (fopen64 (filename, modes));
164
165 #else
166 return close_on_exec (fopen (filename, modes));
167 #endif
168 }
169
170 /*
171 INTERNAL_DEFINITION
172 struct bfd_iovec
173
174 DESCRIPTION
175
176 The <<struct bfd_iovec>> contains the internal file I/O class.
177 Each <<BFD>> has an instance of this class and all file I/O is
178 routed through it (it is assumed that the instance implements
179 all methods listed below).
180
181 .struct bfd_iovec
182 .{
183 . {* To avoid problems with macros, a "b" rather than "f"
184 . prefix is prepended to each method name. *}
185 . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
186 . bytes starting at PTR. Return the number of bytes actually
187 . transfered (a read past end-of-file returns less than NBYTES),
188 . or -1 (setting <<bfd_error>>) if an error occurs. *}
189 . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
190 . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
191 . file_ptr nbytes);
192 . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
193 . if an error occurs. *}
194 . file_ptr (*btell) (struct bfd *abfd);
195 . {* For the following, on successful completion a value of 0 is returned.
196 . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *}
197 . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
198 . int (*bclose) (struct bfd *abfd);
199 . int (*bflush) (struct bfd *abfd);
200 . int (*bstat) (struct bfd *abfd, struct stat *sb);
201 . {* Mmap a part of the files. ADDR, LEN, PROT, FLAGS and OFFSET are the usual
202 . mmap parameter, except that LEN and OFFSET do not need to be page
203 . aligned. Returns (void *)-1 on failure, mmapped address on success.
204 . Also write in MAP_ADDR the address of the page aligned buffer and in
205 . MAP_LEN the size mapped (a page multiple). Use unmap with MAP_ADDR and
206 . MAP_LEN to unmap. *}
207 . void *(*bmmap) (struct bfd *abfd, void *addr, bfd_size_type len,
208 . int prot, int flags, file_ptr offset,
209 . void **map_addr, bfd_size_type *map_len);
210 .};
211
212 .extern const struct bfd_iovec _bfd_memory_iovec;
213
214 */
215
216
217 /* Return value is amount read. */
218
219 bfd_size_type
220 bfd_bread (void *ptr, bfd_size_type size, bfd *abfd)
221 {
222 file_ptr nread;
223 bfd *element_bfd = abfd;
224 ufile_ptr offset = 0;
225
226 while (abfd->my_archive != NULL
227 && !bfd_is_thin_archive (abfd->my_archive))
228 {
229 offset += abfd->origin;
230 abfd = abfd->my_archive;
231 }
232 offset += abfd->origin;
233
234 /* If this is a non-thin archive element, don't read past the end of
235 this element. */
236 if (element_bfd->arelt_data != NULL
237 && element_bfd->my_archive != NULL
238 && !bfd_is_thin_archive (element_bfd->my_archive))
239 {
240 bfd_size_type maxbytes = arelt_size (element_bfd);
241
242 if (abfd->where < offset || abfd->where - offset >= maxbytes)
243 {
244 bfd_set_error (bfd_error_invalid_operation);
245 return -1;
246 }
247 if (abfd->where - offset + size > maxbytes)
248 size = maxbytes - (abfd->where - offset);
249 }
250
251 if (abfd->iovec == NULL)
252 {
253 bfd_set_error (bfd_error_invalid_operation);
254 return -1;
255 }
256
257 nread = abfd->iovec->bread (abfd, ptr, size);
258 if (nread != -1)
259 abfd->where += nread;
260
261 return nread;
262 }
263
264 bfd_size_type
265 bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd)
266 {
267 file_ptr nwrote;
268
269 while (abfd->my_archive != NULL
270 && !bfd_is_thin_archive (abfd->my_archive))
271 abfd = abfd->my_archive;
272
273 if (abfd->iovec == NULL)
274 {
275 bfd_set_error (bfd_error_invalid_operation);
276 return -1;
277 }
278
279 nwrote = abfd->iovec->bwrite (abfd, ptr, size);
280 if (nwrote != -1)
281 abfd->where += nwrote;
282 if ((bfd_size_type) nwrote != size)
283 {
284 #ifdef ENOSPC
285 errno = ENOSPC;
286 #endif
287 bfd_set_error (bfd_error_system_call);
288 }
289 return nwrote;
290 }
291
292 file_ptr
293 bfd_tell (bfd *abfd)
294 {
295 ufile_ptr offset = 0;
296 file_ptr ptr;
297
298 while (abfd->my_archive != NULL
299 && !bfd_is_thin_archive (abfd->my_archive))
300 {
301 offset += abfd->origin;
302 abfd = abfd->my_archive;
303 }
304 offset += abfd->origin;
305
306 if (abfd->iovec == NULL)
307 return 0;
308
309 ptr = abfd->iovec->btell (abfd);
310 abfd->where = ptr;
311 return ptr - offset;
312 }
313
314 int
315 bfd_flush (bfd *abfd)
316 {
317 while (abfd->my_archive != NULL
318 && !bfd_is_thin_archive (abfd->my_archive))
319 abfd = abfd->my_archive;
320
321 if (abfd->iovec == NULL)
322 return 0;
323
324 return abfd->iovec->bflush (abfd);
325 }
326
327 /* Returns 0 for success, negative value for failure (in which case
328 bfd_get_error can retrieve the error code). */
329 int
330 bfd_stat (bfd *abfd, struct stat *statbuf)
331 {
332 int result;
333
334 while (abfd->my_archive != NULL
335 && !bfd_is_thin_archive (abfd->my_archive))
336 abfd = abfd->my_archive;
337
338 if (abfd->iovec == NULL)
339 {
340 bfd_set_error (bfd_error_invalid_operation);
341 return -1;
342 }
343
344 result = abfd->iovec->bstat (abfd, statbuf);
345 if (result < 0)
346 bfd_set_error (bfd_error_system_call);
347 return result;
348 }
349
350 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
351 can retrieve the error code). */
352
353 int
354 bfd_seek (bfd *abfd, file_ptr position, int direction)
355 {
356 int result;
357 ufile_ptr offset = 0;
358
359 while (abfd->my_archive != NULL
360 && !bfd_is_thin_archive (abfd->my_archive))
361 {
362 offset += abfd->origin;
363 abfd = abfd->my_archive;
364 }
365 offset += abfd->origin;
366
367 if (abfd->iovec == NULL)
368 {
369 bfd_set_error (bfd_error_invalid_operation);
370 return -1;
371 }
372
373 /* For the time being, a BFD may not seek to it's end. The problem
374 is that we don't easily have a way to recognize the end of an
375 element in an archive. */
376 BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR);
377
378 if (direction != SEEK_CUR)
379 position += offset;
380
381 if ((direction == SEEK_CUR && position == 0)
382 || (direction == SEEK_SET && (ufile_ptr) position == abfd->where))
383 return 0;
384
385 result = abfd->iovec->bseek (abfd, position, direction);
386 if (result != 0)
387 {
388 /* An EINVAL error probably means that the file offset was
389 absurd. */
390 if (errno == EINVAL)
391 bfd_set_error (bfd_error_file_truncated);
392 else
393 bfd_set_error (bfd_error_system_call);
394 }
395 else
396 {
397 /* Adjust `where' field. */
398 if (direction == SEEK_CUR)
399 abfd->where += position;
400 else
401 abfd->where = position;
402 }
403
404 return result;
405 }
406
407 /*
408 FUNCTION
409 bfd_get_mtime
410
411 SYNOPSIS
412 long bfd_get_mtime (bfd *abfd);
413
414 DESCRIPTION
415 Return the file modification time (as read from the file system, or
416 from the archive header for archive members).
417
418 */
419
420 long
421 bfd_get_mtime (bfd *abfd)
422 {
423 struct stat buf;
424
425 if (abfd->mtime_set)
426 return abfd->mtime;
427
428 if (bfd_stat (abfd, &buf) != 0)
429 return 0;
430
431 abfd->mtime = buf.st_mtime; /* Save value in case anyone wants it */
432 return buf.st_mtime;
433 }
434
435 /*
436 FUNCTION
437 bfd_get_size
438
439 SYNOPSIS
440 ufile_ptr bfd_get_size (bfd *abfd);
441
442 DESCRIPTION
443 Return the file size (as read from file system) for the file
444 associated with BFD @var{abfd}.
445
446 The initial motivation for, and use of, this routine is not
447 so we can get the exact size of the object the BFD applies to, since
448 that might not be generally possible (archive members for example).
449 It would be ideal if someone could eventually modify
450 it so that such results were guaranteed.
451
452 Instead, we want to ask questions like "is this NNN byte sized
453 object I'm about to try read from file offset YYY reasonable?"
454 As as example of where we might do this, some object formats
455 use string tables for which the first <<sizeof (long)>> bytes of the
456 table contain the size of the table itself, including the size bytes.
457 If an application tries to read what it thinks is one of these
458 string tables, without some way to validate the size, and for
459 some reason the size is wrong (byte swapping error, wrong location
460 for the string table, etc.), the only clue is likely to be a read
461 error when it tries to read the table, or a "virtual memory
462 exhausted" error when it tries to allocate 15 bazillon bytes
463 of space for the 15 bazillon byte table it is about to read.
464 This function at least allows us to answer the question, "is the
465 size reasonable?".
466
467 A return value of zero indicates the file size is unknown.
468 */
469
470 ufile_ptr
471 bfd_get_size (bfd *abfd)
472 {
473 /* A size of 0 means we haven't yet called bfd_stat. A size of 1
474 means we have a cached value of 0, ie. unknown. */
475 if (abfd->size <= 1 || bfd_write_p (abfd))
476 {
477 struct stat buf;
478
479 if (abfd->size == 1 && !bfd_write_p (abfd))
480 return 0;
481
482 if (bfd_stat (abfd, &buf) != 0
483 || buf.st_size == 0
484 || buf.st_size - (ufile_ptr) buf.st_size != 0)
485 {
486 abfd->size = 1;
487 return 0;
488 }
489 abfd->size = buf.st_size;
490 }
491 return abfd->size;
492 }
493
494 /*
495 FUNCTION
496 bfd_get_file_size
497
498 SYNOPSIS
499 ufile_ptr bfd_get_file_size (bfd *abfd);
500
501 DESCRIPTION
502 Return the file size (as read from file system) for the file
503 associated with BFD @var{abfd}. It supports both normal files
504 and archive elements.
505
506 */
507
508 ufile_ptr
509 bfd_get_file_size (bfd *abfd)
510 {
511 ufile_ptr file_size, archive_size = (ufile_ptr) -1;
512
513 if (abfd->my_archive != NULL
514 && !bfd_is_thin_archive (abfd->my_archive))
515 {
516 struct areltdata *adata = (struct areltdata *) abfd->arelt_data;
517 if (adata != NULL)
518 {
519 archive_size = adata->parsed_size;
520 /* If the archive is compressed we can't compare against
521 file size. */
522 if (adata->arch_header != NULL
523 && memcmp (((struct ar_hdr *) adata->arch_header)->ar_fmag,
524 "Z\012", 2) == 0)
525 return archive_size;
526 abfd = abfd->my_archive;
527 }
528 }
529
530 file_size = bfd_get_size (abfd);
531 if (archive_size < file_size)
532 return archive_size;
533 return file_size;
534 }
535
536 /*
537 FUNCTION
538 bfd_mmap
539
540 SYNOPSIS
541 void *bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
542 int prot, int flags, file_ptr offset,
543 void **map_addr, bfd_size_type *map_len);
544
545 DESCRIPTION
546 Return mmap()ed region of the file, if possible and implemented.
547 LEN and OFFSET do not need to be page aligned. The page aligned
548 address and length are written to MAP_ADDR and MAP_LEN.
549
550 */
551
552 void *
553 bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
554 int prot, int flags, file_ptr offset,
555 void **map_addr, bfd_size_type *map_len)
556 {
557 while (abfd->my_archive != NULL
558 && !bfd_is_thin_archive (abfd->my_archive))
559 {
560 offset += abfd->origin;
561 abfd = abfd->my_archive;
562 }
563 offset += abfd->origin;
564
565 if (abfd->iovec == NULL)
566 {
567 bfd_set_error (bfd_error_invalid_operation);
568 return (void *) -1;
569 }
570
571 return abfd->iovec->bmmap (abfd, addr, len, prot, flags, offset,
572 map_addr, map_len);
573 }
574
575 /* Memory file I/O operations. */
576
577 static file_ptr
578 memory_bread (bfd *abfd, void *ptr, file_ptr size)
579 {
580 struct bfd_in_memory *bim;
581 bfd_size_type get;
582
583 bim = (struct bfd_in_memory *) abfd->iostream;
584 get = size;
585 if (abfd->where + get > bim->size)
586 {
587 if (bim->size < (bfd_size_type) abfd->where)
588 get = 0;
589 else
590 get = bim->size - abfd->where;
591 bfd_set_error (bfd_error_file_truncated);
592 }
593 memcpy (ptr, bim->buffer + abfd->where, (size_t) get);
594 return get;
595 }
596
597 static file_ptr
598 memory_bwrite (bfd *abfd, const void *ptr, file_ptr size)
599 {
600 struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
601
602 if (abfd->where + size > bim->size)
603 {
604 bfd_size_type newsize, oldsize;
605
606 oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
607 bim->size = abfd->where + size;
608 /* Round up to cut down on memory fragmentation */
609 newsize = (bim->size + 127) & ~(bfd_size_type) 127;
610 if (newsize > oldsize)
611 {
612 bim->buffer = (bfd_byte *) bfd_realloc_or_free (bim->buffer, newsize);
613 if (bim->buffer == NULL)
614 {
615 bim->size = 0;
616 return 0;
617 }
618 if (newsize > bim->size)
619 memset (bim->buffer + bim->size, 0, newsize - bim->size);
620 }
621 }
622 memcpy (bim->buffer + abfd->where, ptr, (size_t) size);
623 return size;
624 }
625
626 static file_ptr
627 memory_btell (bfd *abfd)
628 {
629 return abfd->where;
630 }
631
632 static int
633 memory_bseek (bfd *abfd, file_ptr position, int direction)
634 {
635 file_ptr nwhere;
636 struct bfd_in_memory *bim;
637
638 bim = (struct bfd_in_memory *) abfd->iostream;
639
640 if (direction == SEEK_SET)
641 nwhere = position;
642 else
643 nwhere = abfd->where + position;
644
645 if (nwhere < 0)
646 {
647 abfd->where = 0;
648 errno = EINVAL;
649 return -1;
650 }
651
652 if ((bfd_size_type)nwhere > bim->size)
653 {
654 if (abfd->direction == write_direction
655 || abfd->direction == both_direction)
656 {
657 bfd_size_type newsize, oldsize;
658
659 oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
660 bim->size = nwhere;
661 /* Round up to cut down on memory fragmentation */
662 newsize = (bim->size + 127) & ~(bfd_size_type) 127;
663 if (newsize > oldsize)
664 {
665 bim->buffer = (bfd_byte *) bfd_realloc_or_free (bim->buffer, newsize);
666 if (bim->buffer == NULL)
667 {
668 errno = EINVAL;
669 bim->size = 0;
670 return -1;
671 }
672 memset (bim->buffer + oldsize, 0, newsize - oldsize);
673 }
674 }
675 else
676 {
677 abfd->where = bim->size;
678 errno = EINVAL;
679 bfd_set_error (bfd_error_file_truncated);
680 return -1;
681 }
682 }
683 return 0;
684 }
685
686 static int
687 memory_bclose (struct bfd *abfd)
688 {
689 struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
690
691 free (bim->buffer);
692 free (bim);
693 abfd->iostream = NULL;
694
695 return 0;
696 }
697
698 static int
699 memory_bflush (bfd *abfd ATTRIBUTE_UNUSED)
700 {
701 return 0;
702 }
703
704 static int
705 memory_bstat (bfd *abfd, struct stat *statbuf)
706 {
707 struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
708
709 memset (statbuf, 0, sizeof (*statbuf));
710 statbuf->st_size = bim->size;
711
712 return 0;
713 }
714
715 static void *
716 memory_bmmap (bfd *abfd ATTRIBUTE_UNUSED, void *addr ATTRIBUTE_UNUSED,
717 bfd_size_type len ATTRIBUTE_UNUSED, int prot ATTRIBUTE_UNUSED,
718 int flags ATTRIBUTE_UNUSED, file_ptr offset ATTRIBUTE_UNUSED,
719 void **map_addr ATTRIBUTE_UNUSED,
720 bfd_size_type *map_len ATTRIBUTE_UNUSED)
721 {
722 return (void *)-1;
723 }
724
725 const struct bfd_iovec _bfd_memory_iovec =
726 {
727 &memory_bread, &memory_bwrite, &memory_btell, &memory_bseek,
728 &memory_bclose, &memory_bflush, &memory_bstat, &memory_bmmap
729 };