diff options
Diffstat (limited to 'binutils-2.25/bfd/bfdio.c')
| -rw-r--r-- | binutils-2.25/bfd/bfdio.c | 621 |
1 files changed, 621 insertions, 0 deletions
diff --git a/binutils-2.25/bfd/bfdio.c b/binutils-2.25/bfd/bfdio.c new file mode 100644 index 00000000..363402e9 --- /dev/null +++ b/binutils-2.25/bfd/bfdio.c @@ -0,0 +1,621 @@ +/* Low-level I/O routines for BFDs. + + Copyright 1990-2013 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" + +#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 +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 +} + +/* 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 * +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) + { + /* No attributes. */ + return close_on_exec (fopen (filename, modes)); + } + else + { + /* 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])); + } +#else /* !VMS */ +#if defined (HAVE_FOPEN64) + return close_on_exec (fopen64 (filename, modes)); +#else + return close_on_exec (fopen (filename, modes)); +#endif +#endif /* !VMS */ +} + +/* +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) +{ + size_t nread; + + /* If this is an archive element, don't read past the end of + this element. */ + if (abfd->arelt_data != NULL) + { + bfd_size_type maxbytes = arelt_size (abfd); + + if (abfd->where + size > maxbytes) + { + if (abfd->where >= maxbytes) + return 0; + size = maxbytes - abfd->where; + } + } + + 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->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->iovec) + { + bfd *parent_bfd = abfd; + ptr = abfd->iovec->btell (abfd); + + while (parent_bfd->my_archive != NULL) + { + ptr -= parent_bfd->origin; + parent_bfd = parent_bfd->my_archive; + } + } + else + ptr = 0; + + abfd->where = ptr; + return ptr; +} + +int +bfd_flush (bfd *abfd) +{ + 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->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->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) + { + bfd *parent_bfd = abfd; + + while (parent_bfd->my_archive != NULL) + { + file_position += parent_bfd->origin; + parent_bfd = parent_bfd->my_archive; + } + } + + 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 + file_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?". +*/ + +file_ptr +bfd_get_size (bfd *abfd) +{ + struct stat buf; + + if (abfd->iovec == NULL) + return 0; + + if (abfd->iovec->bstat (abfd, &buf) != 0) + return 0; + + return buf.st_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) +{ + void *ret = (void *)-1; + + if (abfd->iovec == NULL) + return ret; + + 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; + + if (bim->buffer != NULL) + 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 +}; |