binutils-gdb/bfd/compress.c

429 lines
12 KiB
C

/* Compressed section support (intended for debug sections).
Copyright (C) 2008-2014 Free Software Foundation, Inc.
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 "bfd.h"
#include "libbfd.h"
#ifdef HAVE_ZLIB_H
#include <zlib.h>
#endif
#ifdef HAVE_ZLIB_H
static bfd_boolean
decompress_contents (bfd_byte *compressed_buffer,
bfd_size_type compressed_size,
bfd_byte *uncompressed_buffer,
bfd_size_type uncompressed_size)
{
z_stream strm;
int rc;
/* It is possible the section consists of several compressed
buffers concatenated together, so we uncompress in a loop. */
strm.zalloc = NULL;
strm.zfree = NULL;
strm.opaque = NULL;
strm.avail_in = compressed_size - 12;
strm.next_in = (Bytef*) compressed_buffer + 12;
strm.avail_out = uncompressed_size;
BFD_ASSERT (Z_OK == 0);
rc = inflateInit (&strm);
while (strm.avail_in > 0 && strm.avail_out > 0)
{
if (rc != Z_OK)
break;
strm.next_out = ((Bytef*) uncompressed_buffer
+ (uncompressed_size - strm.avail_out));
rc = inflate (&strm, Z_FINISH);
if (rc != Z_STREAM_END)
break;
rc = inflateReset (&strm);
}
rc |= inflateEnd (&strm);
return rc == Z_OK && strm.avail_out == 0;
}
#endif
/*
FUNCTION
bfd_compress_section_contents
SYNOPSIS
bfd_boolean bfd_compress_section_contents
(bfd *abfd, asection *section, bfd_byte *uncompressed_buffer,
bfd_size_type uncompressed_size);
DESCRIPTION
Compress data of the size specified in @var{uncompressed_size}
and pointed to by @var{uncompressed_buffer} using zlib and store
as the contents field. This function assumes the contents
field was allocated using bfd_malloc() or equivalent. If zlib
is not installed on this machine, the input is unmodified.
Return @code{TRUE} if the full section contents is compressed
successfully.
*/
bfd_boolean
bfd_compress_section_contents (bfd *abfd ATTRIBUTE_UNUSED,
sec_ptr sec ATTRIBUTE_UNUSED,
bfd_byte *uncompressed_buffer ATTRIBUTE_UNUSED,
bfd_size_type uncompressed_size ATTRIBUTE_UNUSED)
{
#ifndef HAVE_ZLIB_H
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
#else
uLong compressed_size;
bfd_byte *compressed_buffer;
compressed_size = compressBound (uncompressed_size) + 12;
compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size);
if (compressed_buffer == NULL)
return FALSE;
if (compress ((Bytef*) compressed_buffer + 12,
&compressed_size,
(const Bytef*) uncompressed_buffer,
uncompressed_size) != Z_OK)
{
free (compressed_buffer);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
/* Write the zlib header. In this case, it should be "ZLIB" followed
by the uncompressed section size, 8 bytes in big-endian order. */
memcpy (compressed_buffer, "ZLIB", 4);
compressed_buffer[11] = uncompressed_size; uncompressed_size >>= 8;
compressed_buffer[10] = uncompressed_size; uncompressed_size >>= 8;
compressed_buffer[9] = uncompressed_size; uncompressed_size >>= 8;
compressed_buffer[8] = uncompressed_size; uncompressed_size >>= 8;
compressed_buffer[7] = uncompressed_size; uncompressed_size >>= 8;
compressed_buffer[6] = uncompressed_size; uncompressed_size >>= 8;
compressed_buffer[5] = uncompressed_size; uncompressed_size >>= 8;
compressed_buffer[4] = uncompressed_size;
compressed_size += 12;
/* Free the uncompressed contents if we compress in place. */
if (uncompressed_buffer == sec->contents)
free (uncompressed_buffer);
sec->contents = compressed_buffer;
sec->size = compressed_size;
sec->compress_status = COMPRESS_SECTION_DONE;
return TRUE;
#endif /* HAVE_ZLIB_H */
}
/*
FUNCTION
bfd_get_full_section_contents
SYNOPSIS
bfd_boolean bfd_get_full_section_contents
(bfd *abfd, asection *section, bfd_byte **ptr);
DESCRIPTION
Read all data from @var{section} in BFD @var{abfd}, decompress
if needed, and store in @var{*ptr}. If @var{*ptr} is NULL,
return @var{*ptr} with memory malloc'd by this function.
Return @code{TRUE} if the full section contents is retrieved
successfully.
*/
bfd_boolean
bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
{
bfd_size_type sz;
bfd_byte *p = *ptr;
#ifdef HAVE_ZLIB_H
bfd_boolean ret;
bfd_size_type save_size;
bfd_size_type save_rawsize;
bfd_byte *compressed_buffer;
#endif
if (abfd->direction != write_direction && sec->rawsize != 0)
sz = sec->rawsize;
else
sz = sec->size;
if (sz == 0)
return TRUE;
switch (sec->compress_status)
{
case COMPRESS_SECTION_NONE:
if (p == NULL)
{
p = (bfd_byte *) bfd_malloc (sz);
if (p == NULL)
return FALSE;
}
if (!bfd_get_section_contents (abfd, sec, p, 0, sz))
{
if (*ptr != p)
free (p);
return FALSE;
}
*ptr = p;
return TRUE;
case DECOMPRESS_SECTION_SIZED:
#ifndef HAVE_ZLIB_H
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
#else
/* Read in the full compressed section contents. */
compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size);
if (compressed_buffer == NULL)
return FALSE;
save_rawsize = sec->rawsize;
save_size = sec->size;
/* Clear rawsize, set size to compressed size and set compress_status
to COMPRESS_SECTION_NONE. If the compressed size is bigger than
the uncompressed size, bfd_get_section_contents will fail. */
sec->rawsize = 0;
sec->size = sec->compressed_size;
sec->compress_status = COMPRESS_SECTION_NONE;
ret = bfd_get_section_contents (abfd, sec, compressed_buffer,
0, sec->compressed_size);
/* Restore rawsize and size. */
sec->rawsize = save_rawsize;
sec->size = save_size;
sec->compress_status = DECOMPRESS_SECTION_SIZED;
if (!ret)
goto fail_compressed;
if (p == NULL)
p = (bfd_byte *) bfd_malloc (sz);
if (p == NULL)
goto fail_compressed;
if (!decompress_contents (compressed_buffer, sec->compressed_size, p, sz))
{
bfd_set_error (bfd_error_bad_value);
if (p != *ptr)
free (p);
fail_compressed:
free (compressed_buffer);
return FALSE;
}
free (compressed_buffer);
*ptr = p;
return TRUE;
#endif
case COMPRESS_SECTION_DONE:
if (p == NULL)
{
p = (bfd_byte *) bfd_malloc (sz);
if (p == NULL)
return FALSE;
*ptr = p;
}
memcpy (p, sec->contents, sz);
return TRUE;
default:
abort ();
}
}
/*
FUNCTION
bfd_cache_section_contents
SYNOPSIS
void bfd_cache_section_contents
(asection *sec, void *contents);
DESCRIPTION
Stash @var(contents) so any following reads of @var(sec) do
not need to decompress again.
*/
void
bfd_cache_section_contents (asection *sec, void *contents)
{
if (sec->compress_status == DECOMPRESS_SECTION_SIZED)
sec->compress_status = COMPRESS_SECTION_DONE;
sec->contents = contents;
sec->flags |= SEC_IN_MEMORY;
}
/*
FUNCTION
bfd_is_section_compressed
SYNOPSIS
bfd_boolean bfd_is_section_compressed
(bfd *abfd, asection *section);
DESCRIPTION
Return @code{TRUE} if @var{section} is compressed.
*/
bfd_boolean
bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
{
bfd_byte compressed_buffer [12];
unsigned int saved = sec->compress_status;
bfd_boolean compressed;
/* Don't decompress the section. */
sec->compress_status = COMPRESS_SECTION_NONE;
/* Read the zlib header. In this case, it should be "ZLIB" followed
by the uncompressed section size, 8 bytes in big-endian order. */
compressed = (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)
&& CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"));
/* Restore compress_status. */
sec->compress_status = saved;
return compressed;
}
/*
FUNCTION
bfd_init_section_decompress_status
SYNOPSIS
bfd_boolean bfd_init_section_decompress_status
(bfd *abfd, asection *section);
DESCRIPTION
Record compressed section size, update section size with
decompressed size and set compress_status to
DECOMPRESS_SECTION_SIZED.
Return @code{FALSE} if the section is not a valid compressed
section or zlib is not installed on this machine. Otherwise,
return @code{TRUE}.
*/
bfd_boolean
bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED,
sec_ptr sec ATTRIBUTE_UNUSED)
{
#ifndef HAVE_ZLIB_H
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
#else
bfd_byte compressed_buffer [12];
bfd_size_type uncompressed_size;
if (sec->rawsize != 0
|| sec->contents != NULL
|| sec->compress_status != COMPRESS_SECTION_NONE
|| !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12))
{
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
/* Read the zlib header. In this case, it should be "ZLIB" followed
by the uncompressed section size, 8 bytes in big-endian order. */
if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"))
{
bfd_set_error (bfd_error_wrong_format);
return FALSE;
}
uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[11];
sec->compressed_size = sec->size;
sec->size = uncompressed_size;
sec->compress_status = DECOMPRESS_SECTION_SIZED;
return TRUE;
#endif
}
/*
FUNCTION
bfd_init_section_compress_status
SYNOPSIS
bfd_boolean bfd_init_section_compress_status
(bfd *abfd, asection *section);
DESCRIPTION
If open for read, compress section, update section size with
compressed size and set compress_status to COMPRESS_SECTION_DONE.
Return @code{FALSE} if the section is not a valid compressed
section or zlib is not installed on this machine. Otherwise,
return @code{TRUE}.
*/
bfd_boolean
bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED,
sec_ptr sec ATTRIBUTE_UNUSED)
{
#ifndef HAVE_ZLIB_H
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
#else
bfd_size_type uncompressed_size;
bfd_byte *uncompressed_buffer;
bfd_boolean ret;
/* Error if not opened for read. */
if (abfd->direction != read_direction
|| sec->size == 0
|| sec->rawsize != 0
|| sec->contents != NULL
|| sec->compress_status != COMPRESS_SECTION_NONE)
{
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
/* Read in the full section contents and compress it. */
uncompressed_size = sec->size;
uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer,
0, uncompressed_size))
ret = FALSE;
else
ret = bfd_compress_section_contents (abfd, sec,
uncompressed_buffer,
uncompressed_size);
free (uncompressed_buffer);
return ret;
#endif
}