--- /dev/null
+/*
+ * 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/
+ */
+
+#include "decompress.h"
+#include <xen/lzo.h>
+#include <asm/byteorder.h>
+
+#if 1 /* ndef CONFIG_??? */
+static inline u16 INIT get_unaligned_be16(void *p)
+{
+ return be16_to_cpup(p);
+}
+
+static inline u32 INIT get_unaligned_be32(void *p)
+{
+ return be32_to_cpup(p);
+}
+#else
+#include <asm/unaligned.h>
+
+static inline u16 INIT get_unaligned_be16(void *p)
+{
+ return be16_to_cpu(__get_unaligned(p, 2));
+}
+
+static inline u32 INIT get_unaligned_be32(void *p)
+{
+ return be32_to_cpu(__get_unaligned(p, 4));
+}
+#endif
+
+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
+
+static int INIT parse_header(u8 *input, u8 *skip)
+{
+ int l;
+ u8 *parse = input;
+ u8 level = 0;
+ u16 version;
+
+ /* 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 */
+
+ /* 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 */
+ parse += l + 4;
+
+ *skip = parse - input;
+ return 1;
+}
+
+STATIC int INIT unlzo(u8 *input, unsigned int in_len,
+ int (*fill) (void *, unsigned int),
+ int (*flush) (void *, unsigned int),
+ u8 *output, unsigned int *posp,
+ void (*error_fn) (const char *x))
+{
+ u8 skip = 0, r = 0;
+ u32 src_len, dst_len;
+ size_t tmp;
+ u8 *in_buf, *in_buf_save, *out_buf;
+ int ret = -1;
+
+ set_error_fn(error_fn);
+
+ 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 || !posp) {
+ error("NULL input pointer and missing position pointer or 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)
+ fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
+
+ if (!parse_header(input, &skip)) {
+ error("invalid header");
+ goto exit_2;
+ }
+ in_buf += skip;
+
+ if (posp)
+ *posp = skip;
+
+ for (;;) {
+ /* read uncompressed block size */
+ dst_len = get_unaligned_be32(in_buf);
+ in_buf += 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 */
+ src_len = get_unaligned_be32(in_buf);
+ in_buf += 8;
+
+ if (src_len <= 0 || src_len > dst_len) {
+ error("file corrupted");
+ goto exit_2;
+ }
+
+ /* decompress */
+ 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(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);
+ if (output)
+ out_buf += dst_len;
+ if (posp)
+ *posp += src_len + 12;
+ if (fill) {
+ in_buf = in_buf_save;
+ fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
+ } else
+ in_buf += src_len;
+ }
+
+ ret = 0;
+exit_2:
+ if (!input)
+ free(in_buf);
+exit_1:
+ if (!output)
+ free(out_buf);
+exit:
+ return ret;
+}
projects / xen.git / commitdiff