[PATCH v4 3/6] include/u-boot, lib/zlib: add sources for zlib decompression
Joao Marcos Costa
joaomarcos.costa at bootlin.com
Thu Jul 30 15:33:49 CEST 2020
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 at bootlin.com>
---
Changes in v4:
- Add new config ZLIB_UNCOMPRESS to link zlib's new functionality
only if SquashFS support is enabled.
Changes in v3:
- No changes since v2.
Changes in v2:
- Changed commit title and message, which were wrong and/or misleading
in v1.
fs/squashfs/Kconfig | 1 +
include/u-boot/zlib.h | 32 ++++++++++++++
lib/Kconfig | 7 ++++
lib/zlib/uncompr.c | 97 +++++++++++++++++++++++++++++++++++++++++++
lib/zlib/zlib.c | 3 ++
5 files changed, 140 insertions(+)
create mode 100644 lib/zlib/uncompr.c
diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
index b9772e5619..54ab1618f1 100644
--- 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 e23ceb50ca..a33cc8780d 100644
--- 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 2142bd06e6..089348af73 100644
--- 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
index 0000000000..21e93933b2
--- /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 7e1570292c..90e05e7d4d 100644
--- 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
--
2.17.1
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