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Diffstat (limited to 'libdwfl/gzip.c')
| -rw-r--r-- | libdwfl/gzip.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/libdwfl/gzip.c b/libdwfl/gzip.c new file mode 100644 index 00000000..5604d490 --- /dev/null +++ b/libdwfl/gzip.c @@ -0,0 +1,316 @@ +/* Decompression support for libdwfl: zlib (gzip) and/or bzlib (bzip2). + Copyright (C) 2009 Red Hat, Inc. + This file is part of Red Hat elfutils. + + Red Hat elfutils 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; version 2 of the License. + + Red Hat elfutils 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 Red Hat elfutils; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. + + In addition, as a special exception, Red Hat, Inc. gives You the + additional right to link the code of Red Hat elfutils with code licensed + under any Open Source Initiative certified open source license + (http://www.opensource.org/licenses/index.php) which requires the + distribution of source code with any binary distribution and to + distribute linked combinations of the two. Non-GPL Code permitted under + this exception must only link to the code of Red Hat elfutils through + those well defined interfaces identified in the file named EXCEPTION + found in the source code files (the "Approved Interfaces"). The files + of Non-GPL Code may instantiate templates or use macros or inline + functions from the Approved Interfaces without causing the resulting + work to be covered by the GNU General Public License. Only Red Hat, + Inc. may make changes or additions to the list of Approved Interfaces. + Red Hat's grant of this exception is conditioned upon your not adding + any new exceptions. If you wish to add a new Approved Interface or + exception, please contact Red Hat. You must obey the GNU General Public + License in all respects for all of the Red Hat elfutils code and other + code used in conjunction with Red Hat elfutils except the Non-GPL Code + covered by this exception. If you modify this file, you may extend this + exception to your version of the file, but you are not obligated to do + so. If you do not wish to provide this exception without modification, + you must delete this exception statement from your version and license + this file solely under the GPL without exception. + + Red Hat elfutils is an included package of the Open Invention Network. + An included package of the Open Invention Network is a package for which + Open Invention Network licensees cross-license their patents. No patent + license is granted, either expressly or impliedly, by designation as an + included package. Should you wish to participate in the Open Invention + Network licensing program, please visit www.openinventionnetwork.com + <http://www.openinventionnetwork.com>. */ + +#include "libdwflP.h" +#include "system.h" + +#include <unistd.h> + +#ifdef LZMA +# define USE_INFLATE 1 +# include <lzma.h> +# define unzip __libdw_unlzma +# define DWFL_E_ZLIB DWFL_E_LZMA +# define MAGIC "\xFD" "7zXZ\0" /* XZ file format. */ +# define MAGIC2 "\x5d\0" /* Raw LZMA format. */ +# define Z(what) LZMA_##what +# define LZMA_ERRNO LZMA_PROG_ERROR +# define z_stream lzma_stream +# define inflateInit(z) lzma_auto_decoder (z, 1 << 30, 0) +# define do_inflate(z) lzma_code (z, LZMA_RUN) +# define inflateEnd(z) lzma_end (z) +#elif defined BZLIB +# define USE_INFLATE 1 +# include <bzlib.h> +# define unzip __libdw_bunzip2 +# define DWFL_E_ZLIB DWFL_E_BZLIB +# define MAGIC "BZh" +# define Z(what) BZ_##what +# define BZ_ERRNO BZ_IO_ERROR +# define z_stream bz_stream +# define inflateInit(z) BZ2_bzDecompressInit (z, 0, 0) +# define do_inflate(z) BZ2_bzDecompress (z) +# define inflateEnd(z) BZ2_bzDecompressEnd (z) +#else +# define USE_INFLATE 0 +# define crc32 loser_crc32 +# include <zlib.h> +# define unzip __libdw_gunzip +# define MAGIC "\037\213" +# define Z(what) Z_##what +#endif + +#define READ_SIZE (1 << 20) + +/* If this is not a compressed image, return DWFL_E_BADELF. + If we uncompressed it into *WHOLE, *WHOLE_SIZE, return DWFL_E_NOERROR. + Otherwise return an error for bad compressed data or I/O failure. + If we return an error after reading the first part of the file, + leave that portion malloc'd in *WHOLE, *WHOLE_SIZE. If *WHOLE + is not null on entry, we'll use it in lieu of repeating a read. */ + +Dwfl_Error internal_function +unzip (int fd, off64_t start_offset, + void *mapped, size_t mapped_size, + void **whole, size_t *whole_size) +{ + void *buffer = NULL; + size_t size = 0; + inline bool bigger_buffer (size_t start) + { + size_t more = size ? size * 2 : start; + char *b = realloc (buffer, more); + while (unlikely (b == NULL) && more >= size + 1024) + b = realloc (buffer, more -= 1024); + if (unlikely (b == NULL)) + return false; + buffer = b; + size = more; + return true; + } + inline void smaller_buffer (size_t end) + { + buffer = realloc (buffer, end) ?: end == 0 ? NULL : buffer; + size = end; + } + + void *input_buffer = NULL; + off_t input_pos = 0; + + inline Dwfl_Error fail (Dwfl_Error failure) + { + if (input_pos == (off_t) mapped_size) + *whole = input_buffer; + else + { + free (input_buffer); + *whole = NULL; + } + free (buffer); + return failure; + } + + inline Dwfl_Error zlib_fail (int result) + { + switch (result) + { + case Z (MEM_ERROR): + return fail (DWFL_E_NOMEM); + case Z (ERRNO): + return fail (DWFL_E_ERRNO); + default: + return fail (DWFL_E_ZLIB); + } + } + + if (mapped == NULL) + { + if (*whole == NULL) + { + input_buffer = malloc (READ_SIZE); + if (unlikely (input_buffer == NULL)) + return DWFL_E_NOMEM; + + ssize_t n = pread_retry (fd, input_buffer, READ_SIZE, start_offset); + if (unlikely (n < 0)) + return zlib_fail (Z (ERRNO)); + + input_pos = n; + mapped = input_buffer; + mapped_size = n; + } + else + { + input_buffer = *whole; + input_pos = mapped_size = *whole_size; + } + } + +#define NOMAGIC(magic) \ + (mapped_size <= sizeof magic || memcmp (mapped, magic, sizeof magic - 1)) + + /* First, look at the header. */ + if (NOMAGIC (MAGIC) +#ifdef MAGIC2 + && NOMAGIC (MAGIC2) +#endif + ) + /* Not a compressed file. */ + return DWFL_E_BADELF; + +#if USE_INFLATE + + /* This style actually only works with bzlib and liblzma. + The stupid zlib interface has nothing to grok the + gzip file headers except the slow gzFile interface. */ + + z_stream z = { .next_in = mapped, .avail_in = mapped_size }; + int result = inflateInit (&z); + if (result != Z (OK)) + { + inflateEnd (&z); + return zlib_fail (result); + } + + do + { + if (z.avail_in == 0 && input_buffer != NULL) + { + ssize_t n = pread_retry (fd, input_buffer, READ_SIZE, + start_offset + input_pos); + if (unlikely (n < 0)) + { + inflateEnd (&z); + return zlib_fail (Z (ERRNO)); + } + z.next_in = input_buffer; + z.avail_in = n; + input_pos += n; + } + if (z.avail_out == 0) + { + ptrdiff_t pos = (void *) z.next_out - buffer; + if (!bigger_buffer (z.avail_in)) + { + result = Z (MEM_ERROR); + break; + } + z.next_out = buffer + pos; + z.avail_out = size - pos; + } + } + while ((result = do_inflate (&z)) == Z (OK)); + +#ifdef BZLIB + uint64_t total_out = (((uint64_t) z.total_out_hi32 << 32) + | z.total_out_lo32); + smaller_buffer (total_out); +#else + smaller_buffer (z.total_out); +#endif + + inflateEnd (&z); + + if (result != Z (STREAM_END)) + return zlib_fail (result); + +#else /* gzip only. */ + + /* Let the decompression library read the file directly. */ + + gzFile zf; + Dwfl_Error open_stream (void) + { + int d = dup (fd); + if (unlikely (d < 0)) + return DWFL_E_BADELF; + if (start_offset != 0) + { + off64_t off = lseek (d, start_offset, SEEK_SET); + if (off != start_offset) + { + close (d); + return DWFL_E_BADELF; + } + } + zf = gzdopen (d, "r"); + if (unlikely (zf == NULL)) + { + close (d); + return zlib_fail (Z (MEM_ERROR)); + } + + /* From here on, zlib will close D. */ + + return DWFL_E_NOERROR; + } + + Dwfl_Error result = open_stream (); + + if (result == DWFL_E_NOERROR && gzdirect (zf)) + { + gzclose (zf); + return fail (DWFL_E_BADELF); + } + + if (result != DWFL_E_NOERROR) + return fail (result); + + ptrdiff_t pos = 0; + while (1) + { + if (!bigger_buffer (1024)) + { + gzclose (zf); + return zlib_fail (Z (MEM_ERROR)); + } + int n = gzread (zf, buffer + pos, size - pos); + if (n < 0) + { + int code; + gzerror (zf, &code); + gzclose (zf); + return zlib_fail (code); + } + if (n == 0) + break; + pos += n; + } + + gzclose (zf); + smaller_buffer (pos); +#endif + + free (input_buffer); + + *whole = buffer; + *whole_size = size; + + return DWFL_E_NOERROR; +} |