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-rw-r--r--lib/decompress_unlzo.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/lib/decompress_unlzo.c b/lib/decompress_unlzo.c
new file mode 100644
index 0000000000..64c1358500
--- /dev/null
+++ b/lib/decompress_unlzo.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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.
+ *
+ * Markus F.X.J. Oberhumer
+ * <markus@oberhumer.com>
+ * http://www.oberhumer.com/opensource/lzop/
+ */
+
+#ifdef STATIC
+#define PREBOOT
+#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;
+ 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)
+ 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;
+}
+
+#ifdef PREBOOT
+STATIC int INIT __decompress(unsigned char *buf, long len,
+ long (*fill)(void*, unsigned long),
+ long (*flush)(void*, unsigned long),
+ unsigned char *out_buf, long olen,
+ long *pos,
+ void (*error)(char *x))
+{
+ return unlzo(buf, len, fill, flush, out_buf, pos, error);
+}
+#endif
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