Initial import

1 files changed, 290 insertions, 0 deletions

diff --git a/lib/decompress_unlzo.c b/lib/decompress_unlzo.c
new file mode 100644
index 000000000..b94a31bdd
--- /dev/null
+++ b/lib/decompress_unlzo.c
@@ -0,0 +1,290 @@
+/*
+ * LZO decompressor for the Linux kernel. Code borrowed from the lzo
+ * implementation by Markus Franz Xaver Johannes Oberhumer.
+ *
+ * Linux kernel adaptation:
+ * Copyright (C) 2009
+ * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>
+ *
+ * Original code:
+ * Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
+ * All Rights Reserved.
+ *
+ * lzop and the LZO library are free software; you can redistribute them
+ * and/or modify them under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 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; see the file COPYING.
+ * If not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Markus F.X.J. Oberhumer
+ * <markus@oberhumer.com>
+ * http://www.oberhumer.com/opensource/lzop/
+ */
+
+#ifdef STATIC
+#include "lzo/lzo1x_decompress_safe.c"
+#else
+#include <linux/decompress/unlzo.h>
+#endif
+
+#include <linux/types.h>
+#include <linux/lzo.h>
+#include <linux/decompress/mm.h>
+
+#include <linux/compiler.h>
+#include <asm/unaligned.h>
+
+static const unsigned char lzop_magic[] = {
+	0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };
+
+#define LZO_BLOCK_SIZE        (256*1024l)
+#define HEADER_HAS_FILTER      0x00000800L
+#define HEADER_SIZE_MIN       (9 + 7     + 4 + 8     + 1       + 4)
+#define HEADER_SIZE_MAX       (9 + 7 + 1 + 8 + 8 + 4 + 1 + 255 + 4)
+
+STATIC inline long INIT parse_header(u8 *input, long *skip, long in_len)
+{
+	int l;
+	u8 *parse = input;
+	u8 *end = input + in_len;
+	u8 level = 0;
+	u16 version;
+
+	/*
+	 * Check that there's enough input to possibly have a valid header.
+	 * Then it is possible to parse several fields until the minimum
+	 * size may have been used.
+	 */
+	if (in_len < HEADER_SIZE_MIN)
+		return 0;
+
+	/* read magic: 9 first bits */
+	for (l = 0; l < 9; l++) {
+		if (*parse++ != lzop_magic[l])
+			return 0;
+	}
+	/* get version (2bytes), skip library version (2),
+	 * 'need to be extracted' version (2) and
+	 * method (1) */
+	version = get_unaligned_be16(parse);
+	parse += 7;
+	if (version >= 0x0940)
+		level = *parse++;
+	if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)
+		parse += 8; /* flags + filter info */
+	else
+		parse += 4; /* flags */
+
+	/*
+	 * At least mode, mtime_low, filename length, and checksum must
+	 * be left to be parsed. If also mtime_high is present, it's OK
+	 * because the next input buffer check is after reading the
+	 * filename length.
+	 */
+	if (end - parse < 8 + 1 + 4)
+		return 0;
+
+	/* skip mode and mtime_low */
+	parse += 8;
+	if (version >= 0x0940)
+		parse += 4;	/* skip mtime_high */
+
+	l = *parse++;
+	/* don't care about the file name, and skip checksum */
+	if (end - parse < l + 4)
+		return 0;
+	parse += l + 4;
+
+	*skip = parse - input;
+	return 1;
+}
+
+STATIC int INIT unlzo(u8 *input, long in_len,
+				long (*fill)(void *, unsigned long),
+				long (*flush)(void *, unsigned long),
+				u8 *output, long *posp,
+				void (*error) (char *x))
+{
+	u8 r = 0;
+	long skip = 0;
+	u32 src_len, dst_len;
+	size_t tmp;
+	u8 *in_buf, *in_buf_save, *out_buf;
+	int ret = -1;
+
+	if (output) {
+		out_buf = output;
+	} else if (!flush) {
+		error("NULL output pointer and no flush function provided");
+		goto exit;
+	} else {
+		out_buf = malloc(LZO_BLOCK_SIZE);
+		if (!out_buf) {
+			error("Could not allocate output buffer");
+			goto exit;
+		}
+	}
+
+	if (input && fill) {
+		error("Both input pointer and fill function provided, don't know what to do");
+		goto exit_1;
+	} else if (input) {
+		in_buf = input;
+	} else if (!fill) {
+		error("NULL input pointer and missing fill function");
+		goto exit_1;
+	} else {
+		in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
+		if (!in_buf) {
+			error("Could not allocate input buffer");
+			goto exit_1;
+		}
+	}
+	in_buf_save = in_buf;
+
+	if (posp)
+		*posp = 0;
+
+	if (fill) {
+		/*
+		 * Start from in_buf + HEADER_SIZE_MAX to make it possible
+		 * to use memcpy() to copy the unused data to the beginning
+		 * of the buffer. This way memmove() isn't needed which
+		 * is missing from pre-boot environments of most archs.
+		 */
+		in_buf += HEADER_SIZE_MAX;
+		in_len = fill(in_buf, HEADER_SIZE_MAX);
+	}
+
+	if (!parse_header(in_buf, &skip, in_len)) {
+		error("invalid header");
+		goto exit_2;
+	}
+	in_buf += skip;
+	in_len -= skip;
+
+	if (fill) {
+		/* Move the unused data to the beginning of the buffer. */
+		memcpy(in_buf_save, in_buf, in_len);
+		in_buf = in_buf_save;
+	}
+
+	if (posp)
+		*posp = skip;
+
+	for (;;) {
+		/* read uncompressed block size */
+		if (fill && in_len < 4) {
+			skip = fill(in_buf + in_len, 4 - in_len);
+			if (skip > 0)
+				in_len += skip;
+		}
+		if (in_len < 4) {
+			error("file corrupted");
+			goto exit_2;
+		}
+		dst_len = get_unaligned_be32(in_buf);
+		in_buf += 4;
+		in_len -= 4;
+
+		/* exit if last block */
+		if (dst_len == 0) {
+			if (posp)
+				*posp += 4;
+			break;
+		}
+
+		if (dst_len > LZO_BLOCK_SIZE) {
+			error("dest len longer than block size");
+			goto exit_2;
+		}
+
+		/* read compressed block size, and skip block checksum info */
+		if (fill && in_len < 8) {
+			skip = fill(in_buf + in_len, 8 - in_len);
+			if (skip > 0)
+				in_len += skip;
+		}
+		if (in_len < 8) {
+			error("file corrupted");
+			goto exit_2;
+		}
+		src_len = get_unaligned_be32(in_buf);
+		in_buf += 8;
+		in_len -= 8;
+
+		if (src_len <= 0 || src_len > dst_len) {
+			error("file corrupted");
+			goto exit_2;
+		}
+
+		/* decompress */
+		if (fill && in_len < src_len) {
+			skip = fill(in_buf + in_len, src_len - in_len);
+			if (skip > 0)
+				in_len += skip;
+		}
+		if (in_len < src_len) {
+			error("file corrupted");
+			goto exit_2;
+		}
+		tmp = dst_len;
+
+		/* When the input data is not compressed at all,
+		 * lzo1x_decompress_safe will fail, so call memcpy()
+		 * instead */
+		if (unlikely(dst_len == src_len))
+			memcpy(out_buf, in_buf, src_len);
+		else {
+			r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
+						out_buf, &tmp);
+
+			if (r != LZO_E_OK || dst_len != tmp) {
+				error("Compressed data violation");
+				goto exit_2;
+			}
+		}
+
+		if (flush && flush(out_buf, dst_len) != dst_len)
+			goto exit_2;
+		if (output)
+			out_buf += dst_len;
+		if (posp)
+			*posp += src_len + 12;
+
+		in_buf += src_len;
+		in_len -= src_len;
+		if (fill) {
+			/*
+			 * If there happens to still be unused data left in
+			 * in_buf, move it to the beginning of the buffer.
+			 * Use a loop to avoid memmove() dependency.
+			 */
+			if (in_len > 0)
+				for (skip = 0; skip < in_len; ++skip)
+					in_buf_save[skip] = in_buf[skip];
+			in_buf = in_buf_save;
+		}
+	}
+
+	ret = 0;
+exit_2:
+	if (!input)
+		free(in_buf_save);
+exit_1:
+	if (!output)
+		free(out_buf);
+exit:
+	return ret;
+}
+
+#define decompress unlzo