| /* Low-level I/O routines for BFDs. |
| |
| Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
| 1999, 2000, 2001, 2002, 2003, 2004, 2005 |
| Free Software Foundation, Inc. |
| |
| Written by Cygnus Support. |
| |
| This file is part of BFD, the Binary File Descriptor library. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
| |
| #include "sysdep.h" |
| |
| #include "bfd.h" |
| #include "libbfd.h" |
| |
| #include <limits.h> |
| |
| #ifndef S_IXUSR |
| #define S_IXUSR 0100 /* Execute by owner. */ |
| #endif |
| #ifndef S_IXGRP |
| #define S_IXGRP 0010 /* Execute by group. */ |
| #endif |
| #ifndef S_IXOTH |
| #define S_IXOTH 0001 /* Execute by others. */ |
| #endif |
| |
| file_ptr |
| real_ftell (FILE *file) |
| { |
| #if defined (HAVE_FTELLO64) |
| return ftello64 (file); |
| #elif defined (HAVE_FTELLO) |
| return ftello (file); |
| #else |
| return ftell (file); |
| #endif |
| } |
| |
| int |
| real_fseek (FILE *file, file_ptr offset, int whence) |
| { |
| #if defined (HAVE_FSEEKO64) |
| return fseeko64 (file, offset, whence); |
| #elif defined (HAVE_FSEEKO) |
| return fseeko (file, offset, whence); |
| #else |
| return fseek (file, offset, whence); |
| #endif |
| } |
| |
| /* |
| INTERNAL_DEFINITION |
| struct bfd_iovec |
| |
| DESCRIPTION |
| |
| The <<struct bfd_iovec>> contains the internal file I/O class. |
| Each <<BFD>> has an instance of this class and all file I/O is |
| routed through it (it is assumed that the instance implements |
| all methods listed below). |
| |
| .struct bfd_iovec |
| .{ |
| . {* To avoid problems with macros, a "b" rather than "f" |
| . prefix is prepended to each method name. *} |
| . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching |
| . bytes starting at PTR. Return the number of bytes actually |
| . transfered (a read past end-of-file returns less than NBYTES), |
| . or -1 (setting <<bfd_error>>) if an error occurs. *} |
| . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes); |
| . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr, |
| . file_ptr nbytes); |
| . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>> |
| . if an error occurs. *} |
| . file_ptr (*btell) (struct bfd *abfd); |
| . {* For the following, on successful completion a value of 0 is returned. |
| . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *} |
| . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence); |
| . int (*bclose) (struct bfd *abfd); |
| . int (*bflush) (struct bfd *abfd); |
| . int (*bstat) (struct bfd *abfd, struct stat *sb); |
| .}; |
| |
| */ |
| |
| |
| /* Return value is amount read. */ |
| |
| bfd_size_type |
| bfd_bread (void *ptr, bfd_size_type size, bfd *abfd) |
| { |
| size_t nread; |
| |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| { |
| struct bfd_in_memory *bim; |
| bfd_size_type get; |
| |
| bim = abfd->iostream; |
| get = size; |
| if (abfd->where + get > bim->size) |
| { |
| if (bim->size < (bfd_size_type) abfd->where) |
| get = 0; |
| else |
| get = bim->size - abfd->where; |
| bfd_set_error (bfd_error_file_truncated); |
| } |
| memcpy (ptr, bim->buffer + abfd->where, (size_t) get); |
| abfd->where += get; |
| return get; |
| } |
| |
| if (abfd->iovec) |
| nread = abfd->iovec->bread (abfd, ptr, size); |
| else |
| nread = 0; |
| if (nread != (size_t) -1) |
| abfd->where += nread; |
| |
| return nread; |
| } |
| |
| bfd_size_type |
| bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd) |
| { |
| size_t nwrote; |
| |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| { |
| struct bfd_in_memory *bim = abfd->iostream; |
| |
| size = (size_t) size; |
| if (abfd->where + size > bim->size) |
| { |
| bfd_size_type newsize, oldsize; |
| |
| oldsize = (bim->size + 127) & ~(bfd_size_type) 127; |
| bim->size = abfd->where + size; |
| /* Round up to cut down on memory fragmentation */ |
| newsize = (bim->size + 127) & ~(bfd_size_type) 127; |
| if (newsize > oldsize) |
| { |
| bim->buffer = bfd_realloc (bim->buffer, newsize); |
| if (bim->buffer == 0) |
| { |
| bim->size = 0; |
| return 0; |
| } |
| } |
| } |
| memcpy (bim->buffer + abfd->where, ptr, (size_t) size); |
| abfd->where += size; |
| return size; |
| } |
| |
| if (abfd->iovec) |
| nwrote = abfd->iovec->bwrite (abfd, ptr, size); |
| else |
| nwrote = 0; |
| |
| if (nwrote != (size_t) -1) |
| abfd->where += nwrote; |
| if (nwrote != size) |
| { |
| #ifdef ENOSPC |
| errno = ENOSPC; |
| #endif |
| bfd_set_error (bfd_error_system_call); |
| } |
| return nwrote; |
| } |
| |
| file_ptr |
| bfd_tell (bfd *abfd) |
| { |
| file_ptr ptr; |
| |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| return abfd->where; |
| |
| if (abfd->iovec) |
| { |
| ptr = abfd->iovec->btell (abfd); |
| |
| if (abfd->my_archive) |
| ptr -= abfd->origin; |
| } |
| else |
| ptr = 0; |
| |
| abfd->where = ptr; |
| return ptr; |
| } |
| |
| int |
| bfd_flush (bfd *abfd) |
| { |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| return 0; |
| |
| if (abfd->iovec) |
| return abfd->iovec->bflush (abfd); |
| return 0; |
| } |
| |
| /* Returns 0 for success, negative value for failure (in which case |
| bfd_get_error can retrieve the error code). */ |
| int |
| bfd_stat (bfd *abfd, struct stat *statbuf) |
| { |
| int result; |
| |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| abort (); |
| |
| if (abfd->iovec) |
| result = abfd->iovec->bstat (abfd, statbuf); |
| else |
| result = -1; |
| |
| if (result < 0) |
| bfd_set_error (bfd_error_system_call); |
| return result; |
| } |
| |
| /* Returns 0 for success, nonzero for failure (in which case bfd_get_error |
| can retrieve the error code). */ |
| |
| int |
| bfd_seek (bfd *abfd, file_ptr position, int direction) |
| { |
| int result; |
| file_ptr file_position; |
| /* For the time being, a BFD may not seek to it's end. The problem |
| is that we don't easily have a way to recognize the end of an |
| element in an archive. */ |
| |
| BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR); |
| |
| if (direction == SEEK_CUR && position == 0) |
| return 0; |
| |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| { |
| struct bfd_in_memory *bim; |
| |
| bim = abfd->iostream; |
| |
| if (direction == SEEK_SET) |
| abfd->where = position; |
| else |
| abfd->where += position; |
| |
| if (abfd->where > bim->size) |
| { |
| if ((abfd->direction == write_direction) || |
| (abfd->direction == both_direction)) |
| { |
| bfd_size_type newsize, oldsize; |
| |
| oldsize = (bim->size + 127) & ~(bfd_size_type) 127; |
| bim->size = abfd->where; |
| /* Round up to cut down on memory fragmentation */ |
| newsize = (bim->size + 127) & ~(bfd_size_type) 127; |
| if (newsize > oldsize) |
| { |
| bim->buffer = bfd_realloc (bim->buffer, newsize); |
| if (bim->buffer == 0) |
| { |
| bim->size = 0; |
| return -1; |
| } |
| } |
| } |
| else |
| { |
| abfd->where = bim->size; |
| bfd_set_error (bfd_error_file_truncated); |
| return -1; |
| } |
| } |
| return 0; |
| } |
| |
| if (abfd->format != bfd_archive && abfd->my_archive == 0) |
| { |
| if (direction == SEEK_SET && (bfd_vma) position == abfd->where) |
| return 0; |
| } |
| else |
| { |
| /* We need something smarter to optimize access to archives. |
| Currently, anything inside an archive is read via the file |
| handle for the archive. Which means that a bfd_seek on one |
| component affects the `current position' in the archive, as |
| well as in any other component. |
| |
| It might be sufficient to put a spike through the cache |
| abstraction, and look to the archive for the file position, |
| but I think we should try for something cleaner. |
| |
| In the meantime, no optimization for archives. */ |
| } |
| |
| file_position = position; |
| if (direction == SEEK_SET && abfd->my_archive != NULL) |
| file_position += abfd->origin; |
| |
| if (abfd->iovec) |
| result = abfd->iovec->bseek (abfd, file_position, direction); |
| else |
| result = -1; |
| |
| if (result != 0) |
| { |
| int hold_errno = errno; |
| |
| /* Force redetermination of `where' field. */ |
| bfd_tell (abfd); |
| |
| /* An EINVAL error probably means that the file offset was |
| absurd. */ |
| if (hold_errno == EINVAL) |
| bfd_set_error (bfd_error_file_truncated); |
| else |
| { |
| bfd_set_error (bfd_error_system_call); |
| errno = hold_errno; |
| } |
| } |
| else |
| { |
| /* Adjust `where' field. */ |
| if (direction == SEEK_SET) |
| abfd->where = position; |
| else |
| abfd->where += position; |
| } |
| return result; |
| } |
| |
| /* |
| FUNCTION |
| bfd_get_mtime |
| |
| SYNOPSIS |
| long bfd_get_mtime (bfd *abfd); |
| |
| DESCRIPTION |
| Return the file modification time (as read from the file system, or |
| from the archive header for archive members). |
| |
| */ |
| |
| long |
| bfd_get_mtime (bfd *abfd) |
| { |
| struct stat buf; |
| |
| if (abfd->mtime_set) |
| return abfd->mtime; |
| |
| if (abfd->iovec == NULL) |
| return 0; |
| |
| if (abfd->iovec->bstat (abfd, &buf) != 0) |
| return 0; |
| |
| abfd->mtime = buf.st_mtime; /* Save value in case anyone wants it */ |
| return buf.st_mtime; |
| } |
| |
| /* |
| FUNCTION |
| bfd_get_size |
| |
| SYNOPSIS |
| long bfd_get_size (bfd *abfd); |
| |
| DESCRIPTION |
| Return the file size (as read from file system) for the file |
| associated with BFD @var{abfd}. |
| |
| The initial motivation for, and use of, this routine is not |
| so we can get the exact size of the object the BFD applies to, since |
| that might not be generally possible (archive members for example). |
| It would be ideal if someone could eventually modify |
| it so that such results were guaranteed. |
| |
| Instead, we want to ask questions like "is this NNN byte sized |
| object I'm about to try read from file offset YYY reasonable?" |
| As as example of where we might do this, some object formats |
| use string tables for which the first <<sizeof (long)>> bytes of the |
| table contain the size of the table itself, including the size bytes. |
| If an application tries to read what it thinks is one of these |
| string tables, without some way to validate the size, and for |
| some reason the size is wrong (byte swapping error, wrong location |
| for the string table, etc.), the only clue is likely to be a read |
| error when it tries to read the table, or a "virtual memory |
| exhausted" error when it tries to allocate 15 bazillon bytes |
| of space for the 15 bazillon byte table it is about to read. |
| This function at least allows us to answer the question, "is the |
| size reasonable?". |
| */ |
| |
| long |
| bfd_get_size (bfd *abfd) |
| { |
| struct stat buf; |
| |
| if ((abfd->flags & BFD_IN_MEMORY) != 0) |
| return ((struct bfd_in_memory *) abfd->iostream)->size; |
| |
| if (abfd->iovec == NULL) |
| return 0; |
| |
| if (abfd->iovec->bstat (abfd, &buf) != 0) |
| return 0; |
| |
| return buf.st_size; |
| } |