include/u-boot, lib/zlib: add sources for zlib decompression

Add zlib (v1.2.11) uncompr() function to U-Boot. SquashFS depends on
this function to decompress data from a raw disk image. The actual
support for zlib into SquashFS sources will be added in a follow-up
commit.

Signed-off-by: Joao Marcos Costa <joaomarcos.costa@bootlin.com>

diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
index b9772e5..54ab161 100644 (file)
--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -1,5 +1,6 @@
 config FS_SQUASHFS
        bool "Enable SquashFS filesystem support"
+       select ZLIB_UNCOMPRESS
        help
          This provides support for reading images from SquashFS filesystem.
          Squashfs is a compressed read-only filesystem for Linux.

diff --git a/include/u-boot/zlib.h b/include/u-boot/zlib.h
index e23ceb5..a33cc87 100644 (file)
--- a/include/u-boot/zlib.h
+++ b/include/u-boot/zlib.h
@@ -110,6 +110,12 @@ extern "C" {
 #  define voidp                 z_voidp
 #endif
 
+#if defined(ZLIB_CONST) && !defined(z_const)
+#  define z_const const
+#else
+#  define z_const
+#endif
+
 #if defined(__MSDOS__) && !defined(MSDOS)
 #  define MSDOS
 #endif
@@ -710,6 +716,32 @@ ZEXTERN  uInt ZEXPORT crc32  OF((uInt crc, const Bytef *buf, uInt len));
      if (crc != original_crc) error();
 */
 
+ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
+                                  const Bytef *source, uLong sourceLen));
+/*
+     Decompresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer.  Upon entry, destLen is the total size
+   of the destination buffer, which must be large enough to hold the entire
+   uncompressed data.  (The size of the uncompressed data must have been saved
+   previously by the compressor and transmitted to the decompressor by some
+   mechanism outside the scope of this compression library.) Upon exit, destLen
+   is the actual size of the uncompressed data.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In
+   the case where there is not enough room, uncompress() will fill the output
+   buffer with the uncompressed data up to that point.
+*/
+
+ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen,
+                                   const Bytef *source, uLong *sourceLen));
+/*
+     Same as uncompress, except that sourceLen is a pointer, where the
+   length of the source is *sourceLen.  On return, *sourceLen is the number of
+   source bytes consumed.
+*/
+
 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
                                       const char *version, int stream_size));
 #define inflateInit(strm) \

diff --git a/lib/Kconfig b/lib/Kconfig
index 2142bd0..089348a 100644 (file)
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -460,6 +460,13 @@ config GZIP
        help
          This enables support for GZIP compression algorithm.
 
+config ZLIB_UNCOMPRESS
+       bool "Enables zlib's uncompress() functionality"
+       help
+         This enables an extra zlib functionality: the uncompress() function,
+         which decompresses data from a buffer into another, knowing their
+         sizes. Unlike gunzip(), there is no header parsing.
+
 config GZIP_COMPRESSED
        bool
        select ZLIB

diff --git a/lib/zlib/uncompr.c b/lib/zlib/uncompr.c
new file mode 100644 (file)
index 0000000..21e9393
--- /dev/null
+++ b/lib/zlib/uncompr.c
@@ -0,0 +1,97 @@
+/* uncompr.c -- decompress a memory buffer
+ * Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#define ZLIB_INTERNAL
+#include "zlib.h"
+
+/* ===========================================================================
+     Decompresses the source buffer into the destination buffer.  *sourceLen is
+   the byte length of the source buffer. Upon entry, *destLen is the total size
+   of the destination buffer, which must be large enough to hold the entire
+   uncompressed data. (The size of the uncompressed data must have been saved
+   previously by the compressor and transmitted to the decompressor by some
+   mechanism outside the scope of this compression library.) Upon exit,
+   *destLen is the size of the decompressed data and *sourceLen is the number
+   of source bytes consumed. Upon return, source + *sourceLen points to the
+   first unused input byte.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer, or
+   Z_DATA_ERROR if the input data was corrupted, including if the input data is
+   an incomplete zlib stream.
+*/
+int ZEXPORT uncompress2(dest, destLen, source, sourceLen)
+       Bytef *dest;
+       uLongf *destLen;
+       const Bytef *source;
+       uLong *sourceLen;
+
+{
+       z_stream stream;
+       int err;
+       const uInt max = (uInt)-1;
+       uLong len, left;
+       /* for detection of incomplete stream when *destLen == 0 */
+       Byte buf[1];
+
+       len = *sourceLen;
+       if (*destLen) {
+               left = *destLen;
+               *destLen = 0;
+       } else {
+               left = 1;
+               dest = buf;
+       }
+
+       stream.next_in = (z_const Bytef *)source;
+       stream.avail_in = 0;
+       stream.zalloc = (alloc_func)0;
+       stream.zfree = (free_func)0;
+       stream.opaque = (voidpf)0;
+
+       err = inflateInit(&stream);
+       if (err != Z_OK)
+               return err;
+
+       stream.next_out = dest;
+       stream.avail_out = 0;
+
+       do {
+               if (stream.avail_out == 0) {
+                       stream.avail_out = left > (uLong)max ? max : (uInt)left;
+                       left -= stream.avail_out;
+               }
+
+               if (stream.avail_in == 0) {
+                       stream.avail_in = len > (uLong)max ? max : (uInt)len;
+                       len -= stream.avail_in;
+               }
+
+               err = inflate(&stream, Z_NO_FLUSH);
+       } while (err == Z_OK);
+
+       *sourceLen -= len + stream.avail_in;
+       if (dest != buf)
+               *destLen = stream.total_out;
+       else if (stream.total_out && err == Z_BUF_ERROR)
+               left = 1;
+
+       inflateEnd(&stream);
+       return err == Z_STREAM_END ? Z_OK :
+               err == Z_NEED_DICT ? Z_DATA_ERROR  :
+               err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
+               err;
+}
+
+int ZEXPORT uncompress(dest, destLen, source, sourceLen)
+       Bytef *dest;
+       uLongf *destLen;
+       const Bytef *source;
+       uLong sourceLen;
+{
+       return uncompress2(dest, destLen, source, &sourceLen);
+}

diff --git a/lib/zlib/zlib.c b/lib/zlib/zlib.c
index 7e15702..90e05e7 100644 (file)
--- a/lib/zlib/zlib.c
+++ b/lib/zlib/zlib.c
@@ -30,3 +30,6 @@
 #include "inflate.c"
 #include "zutil.c"
 #include "adler32.c"
+#if IS_ENABLED(CONFIG_ZLIB_UNCOMPRESS)
+#include "uncompr.c"
+#endif