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- /* Low-level I/O routines for BFDs.
- Copyright (C) 1990-2022 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 3 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 <limits.h>
- #include "bfd.h"
- #include "libbfd.h"
- #include "aout/ar.h"
- #if defined (_WIN32)
- #include <windows.h>
- #endif
- #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
- #ifndef FD_CLOEXEC
- #define FD_CLOEXEC 1
- #endif
- file_ptr
- _bfd_real_ftell (FILE *file)
- {
- #if defined (HAVE_FTELLO64)
- return ftello64 (file);
- #elif defined (HAVE_FTELLO)
- return ftello (file);
- #else
- return ftell (file);
- #endif
- }
- int
- _bfd_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
- }
- /* Mark FILE as close-on-exec. Return FILE. FILE may be NULL, in
- which case nothing is done. */
- static FILE *
- close_on_exec (FILE *file)
- {
- #if defined (HAVE_FILENO) && defined (F_GETFD)
- if (file)
- {
- int fd = fileno (file);
- int old = fcntl (fd, F_GETFD, 0);
- if (old >= 0)
- fcntl (fd, F_SETFD, old | FD_CLOEXEC);
- }
- #endif
- return file;
- }
- FILE *
- _bfd_real_fopen (const char *filename, const char *modes)
- {
- #ifdef VMS
- char *vms_attr;
- /* On VMS, fopen allows file attributes as optional arguments.
- We need to use them but we'd better to use the common prototype.
- In fopen-vms.h, they are separated from the mode with a comma.
- Split here. */
- vms_attr = strchr (modes, ',');
- if (vms_attr != NULL)
- {
- /* Attributes found. Split. */
- size_t modes_len = strlen (modes) + 1;
- char attrs[modes_len + 1];
- char *at[3];
- int i;
- memcpy (attrs, modes, modes_len);
- at[0] = attrs;
- for (i = 0; i < 2; i++)
- {
- at[i + 1] = strchr (at[i], ',');
- BFD_ASSERT (at[i + 1] != NULL);
- *(at[i + 1]++) = 0; /* Replace ',' with a nul, and skip it. */
- }
- return close_on_exec (fopen (filename, at[0], at[1], at[2]));
- }
- #elif defined (_WIN32)
- /* PR 25713: Handle extra long path names possibly containing '..' and '.'. */
- wchar_t ** lpFilePart = {NULL};
- const wchar_t prefix[] = L"\\\\?\\";
- const wchar_t ccs[] = L", ccs=UNICODE";
- const size_t partPathLen = strlen (filename) + 1;
- /* Converting the partial path from ascii to unicode.
- 1) Get the length: Calling with lpWideCharStr set to null returns the length.
- 2) Convert the string: Calling with cbMultiByte set to -1 includes the terminating null. */
- size_t partPathWSize = MultiByteToWideChar (CP_UTF8, 0, filename, -1, NULL, 0);
- wchar_t * partPath = calloc (partPathWSize, sizeof(wchar_t));
- size_t ix;
- MultiByteToWideChar (CP_UTF8, 0, filename, -1, partPath, partPathWSize);
- /* Convert any UNIX style path separators into the DOS i.e. backslash separator. */
- for (ix = 0; ix < partPathLen; ix++)
- if (IS_UNIX_DIR_SEPARATOR(filename[ix]))
- partPath[ix] = '\\';
- /* Getting the full path from the provided partial path.
- 1) Get the length.
- 2) Resolve the path. */
- long fullPathWSize = GetFullPathNameW (partPath, 0, NULL, lpFilePart);
- wchar_t * fullPath = calloc (fullPathWSize + sizeof(prefix) + 1, sizeof(wchar_t));
- wcscpy (fullPath, prefix);
- int prefixLen = sizeof(prefix) / sizeof(wchar_t);
- wchar_t * fullPathOffset = fullPath + prefixLen - 1;
- GetFullPathNameW (partPath, fullPathWSize, fullPathOffset, lpFilePart);
- free (partPath);
- /* It is non-standard for modes to exceed 16 characters. */
- wchar_t modesW[16 + sizeof(ccs)];
- MultiByteToWideChar (CP_UTF8, 0, modes, -1, modesW, sizeof(modesW));
- wcscat (modesW, ccs);
- FILE * file = _wfopen (fullPath, modesW);
- free (fullPath);
- return close_on_exec (file);
- #elif defined (HAVE_FOPEN64)
- return close_on_exec (fopen64 (filename, modes));
- #else
- return close_on_exec (fopen (filename, modes));
- #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);
- . {* Mmap a part of the files. ADDR, LEN, PROT, FLAGS and OFFSET are the usual
- . mmap parameter, except that LEN and OFFSET do not need to be page
- . aligned. Returns (void *)-1 on failure, mmapped address on success.
- . Also write in MAP_ADDR the address of the page aligned buffer and in
- . MAP_LEN the size mapped (a page multiple). Use unmap with MAP_ADDR and
- . MAP_LEN to unmap. *}
- . void *(*bmmap) (struct bfd *abfd, void *addr, bfd_size_type len,
- . int prot, int flags, file_ptr offset,
- . void **map_addr, bfd_size_type *map_len);
- .};
- .extern const struct bfd_iovec _bfd_memory_iovec;
- */
- /* Return value is amount read. */
- bfd_size_type
- bfd_bread (void *ptr, bfd_size_type size, bfd *abfd)
- {
- file_ptr nread;
- bfd *element_bfd = abfd;
- ufile_ptr offset = 0;
- while (abfd->my_archive != NULL
- && !bfd_is_thin_archive (abfd->my_archive))
- {
- offset += abfd->origin;
- abfd = abfd->my_archive;
- }
- offset += abfd->origin;
- /* If this is a non-thin archive element, don't read past the end of
- this element. */
- if (element_bfd->arelt_data != NULL
- && element_bfd->my_archive != NULL
- && !bfd_is_thin_archive (element_bfd->my_archive))
- {
- bfd_size_type maxbytes = arelt_size (element_bfd);
- if (abfd->where < offset || abfd->where - offset >= maxbytes)
- {
- bfd_set_error (bfd_error_invalid_operation);
- return -1;
- }
- if (abfd->where - offset + size > maxbytes)
- size = maxbytes - (abfd->where - offset);
- }
- if (abfd->iovec == NULL)
- {
- bfd_set_error (bfd_error_invalid_operation);
- return -1;
- }
- nread = abfd->iovec->bread (abfd, ptr, size);
- if (nread != -1)
- abfd->where += nread;
- return nread;
- }
- bfd_size_type
- bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd)
- {
- file_ptr nwrote;
- while (abfd->my_archive != NULL
- && !bfd_is_thin_archive (abfd->my_archive))
- abfd = abfd->my_archive;
- if (abfd->iovec == NULL)
- {
- bfd_set_error (bfd_error_invalid_operation);
- return -1;
- }
- nwrote = abfd->iovec->bwrite (abfd, ptr, size);
- if (nwrote != -1)
- abfd->where += nwrote;
- if ((bfd_size_type) nwrote != size)
- {
- #ifdef ENOSPC
- errno = ENOSPC;
- #endif
- bfd_set_error (bfd_error_system_call);
- }
- return nwrote;
- }
- file_ptr
- bfd_tell (bfd *abfd)
- {
- ufile_ptr offset = 0;
- file_ptr ptr;
- while (abfd->my_archive != NULL
- && !bfd_is_thin_archive (abfd->my_archive))
- {
- offset += abfd->origin;
- abfd = abfd->my_archive;
- }
- offset += abfd->origin;
- if (abfd->iovec == NULL)
- return 0;
- ptr = abfd->iovec->btell (abfd);
- abfd->where = ptr;
- return ptr - offset;
- }
- int
- bfd_flush (bfd *abfd)
- {
- while (abfd->my_archive != NULL
- && !bfd_is_thin_archive (abfd->my_archive))
- abfd = abfd->my_archive;
- if (abfd->iovec == NULL)
- return 0;
- return abfd->iovec->bflush (abfd);
- }
- /* 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;
- while (abfd->my_archive != NULL
- && !bfd_is_thin_archive (abfd->my_archive))
- abfd = abfd->my_archive;
- if (abfd->iovec == NULL)
- {
- bfd_set_error (bfd_error_invalid_operation);
- return -1;
- }
- result = abfd->iovec->bstat (abfd, statbuf);
- 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;
- ufile_ptr offset = 0;
- while (abfd->my_archive != NULL
- && !bfd_is_thin_archive (abfd->my_archive))
- {
- offset += abfd->origin;
- abfd = abfd->my_archive;
- }
- offset += abfd->origin;
- if (abfd->iovec == NULL)
- {
- bfd_set_error (bfd_error_invalid_operation);
- return -1;
- }
- /* 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 += offset;
- if ((direction == SEEK_CUR && position == 0)
- || (direction == SEEK_SET && (ufile_ptr) position == abfd->where))
- return 0;
- result = abfd->iovec->bseek (abfd, position, direction);
- if (result != 0)
- {
- /* An EINVAL error probably means that the file offset was
- absurd. */
- if (errno == EINVAL)
- bfd_set_error (bfd_error_file_truncated);
- else
- bfd_set_error (bfd_error_system_call);
- }
- else
- {
- /* Adjust `where' field. */
- if (direction == SEEK_CUR)
- 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 (bfd_stat (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
- ufile_ptr 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?".
- A return value of zero indicates the file size is unknown.
- */
- ufile_ptr
- bfd_get_size (bfd *abfd)
- {
- /* A size of 0 means we haven't yet called bfd_stat. A size of 1
- means we have a cached value of 0, ie. unknown. */
- if (abfd->size <= 1 || bfd_write_p (abfd))
- {
- struct stat buf;
- if (abfd->size == 1 && !bfd_write_p (abfd))
- return 0;
- if (bfd_stat (abfd, &buf) != 0
- || buf.st_size == 0
- || buf.st_size - (ufile_ptr) buf.st_size != 0)
- {
- abfd->size = 1;
- return 0;
- }
- abfd->size = buf.st_size;
- }
- return abfd->size;
- }
- /*
- FUNCTION
- bfd_get_file_size
- SYNOPSIS
- ufile_ptr bfd_get_file_size (bfd *abfd);
- DESCRIPTION
- Return the file size (as read from file system) for the file
- associated with BFD @var{abfd}. It supports both normal files
- and archive elements.
- */
- ufile_ptr
- bfd_get_file_size (bfd *abfd)
- {
- ufile_ptr file_size, archive_size = (ufile_ptr) -1;
- if (abfd->my_archive != NULL
- && !bfd_is_thin_archive (abfd->my_archive))
- {
- struct areltdata *adata = (struct areltdata *) abfd->arelt_data;
- if (adata != NULL)
- {
- archive_size = adata->parsed_size;
- /* If the archive is compressed we can't compare against
- file size. */
- if (adata->arch_header != NULL
- && memcmp (((struct ar_hdr *) adata->arch_header)->ar_fmag,
- "Z\012", 2) == 0)
- return archive_size;
- abfd = abfd->my_archive;
- }
- }
- file_size = bfd_get_size (abfd);
- if (archive_size < file_size)
- return archive_size;
- return file_size;
- }
- /*
- FUNCTION
- bfd_mmap
- SYNOPSIS
- void *bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
- int prot, int flags, file_ptr offset,
- void **map_addr, bfd_size_type *map_len);
- DESCRIPTION
- Return mmap()ed region of the file, if possible and implemented.
- LEN and OFFSET do not need to be page aligned. The page aligned
- address and length are written to MAP_ADDR and MAP_LEN.
- */
- void *
- bfd_mmap (bfd *abfd, void *addr, bfd_size_type len,
- int prot, int flags, file_ptr offset,
- void **map_addr, bfd_size_type *map_len)
- {
- while (abfd->my_archive != NULL
- && !bfd_is_thin_archive (abfd->my_archive))
- {
- offset += abfd->origin;
- abfd = abfd->my_archive;
- }
- offset += abfd->origin;
- if (abfd->iovec == NULL)
- {
- bfd_set_error (bfd_error_invalid_operation);
- return (void *) -1;
- }
- return abfd->iovec->bmmap (abfd, addr, len, prot, flags, offset,
- map_addr, map_len);
- }
- /* Memory file I/O operations. */
- static file_ptr
- memory_bread (bfd *abfd, void *ptr, file_ptr size)
- {
- struct bfd_in_memory *bim;
- bfd_size_type get;
- bim = (struct bfd_in_memory *) 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);
- return get;
- }
- static file_ptr
- memory_bwrite (bfd *abfd, const void *ptr, file_ptr size)
- {
- struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
- 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_byte *) bfd_realloc_or_free (bim->buffer, newsize);
- if (bim->buffer == NULL)
- {
- bim->size = 0;
- return 0;
- }
- if (newsize > bim->size)
- memset (bim->buffer + bim->size, 0, newsize - bim->size);
- }
- }
- memcpy (bim->buffer + abfd->where, ptr, (size_t) size);
- return size;
- }
- static file_ptr
- memory_btell (bfd *abfd)
- {
- return abfd->where;
- }
- static int
- memory_bseek (bfd *abfd, file_ptr position, int direction)
- {
- file_ptr nwhere;
- struct bfd_in_memory *bim;
- bim = (struct bfd_in_memory *) abfd->iostream;
- if (direction == SEEK_SET)
- nwhere = position;
- else
- nwhere = abfd->where + position;
- if (nwhere < 0)
- {
- abfd->where = 0;
- errno = EINVAL;
- return -1;
- }
- if ((bfd_size_type)nwhere > 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 = nwhere;
- /* Round up to cut down on memory fragmentation */
- newsize = (bim->size + 127) & ~(bfd_size_type) 127;
- if (newsize > oldsize)
- {
- bim->buffer = (bfd_byte *) bfd_realloc_or_free (bim->buffer, newsize);
- if (bim->buffer == NULL)
- {
- errno = EINVAL;
- bim->size = 0;
- return -1;
- }
- memset (bim->buffer + oldsize, 0, newsize - oldsize);
- }
- }
- else
- {
- abfd->where = bim->size;
- errno = EINVAL;
- bfd_set_error (bfd_error_file_truncated);
- return -1;
- }
- }
- return 0;
- }
- static int
- memory_bclose (struct bfd *abfd)
- {
- struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
- free (bim->buffer);
- free (bim);
- abfd->iostream = NULL;
- return 0;
- }
- static int
- memory_bflush (bfd *abfd ATTRIBUTE_UNUSED)
- {
- return 0;
- }
- static int
- memory_bstat (bfd *abfd, struct stat *statbuf)
- {
- struct bfd_in_memory *bim = (struct bfd_in_memory *) abfd->iostream;
- memset (statbuf, 0, sizeof (*statbuf));
- statbuf->st_size = bim->size;
- return 0;
- }
- static void *
- memory_bmmap (bfd *abfd ATTRIBUTE_UNUSED, void *addr ATTRIBUTE_UNUSED,
- bfd_size_type len ATTRIBUTE_UNUSED, int prot ATTRIBUTE_UNUSED,
- int flags ATTRIBUTE_UNUSED, file_ptr offset ATTRIBUTE_UNUSED,
- void **map_addr ATTRIBUTE_UNUSED,
- bfd_size_type *map_len ATTRIBUTE_UNUSED)
- {
- return (void *)-1;
- }
- const struct bfd_iovec _bfd_memory_iovec =
- {
- &memory_bread, &memory_bwrite, &memory_btell, &memory_bseek,
- &memory_bclose, &memory_bflush, &memory_bstat, &memory_bmmap
- };
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