summaryrefslogtreecommitdiff
path: root/lib/lzo/lzo1x_decompress.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/lzo/lzo1x_decompress.c')
-rw-r--r--lib/lzo/lzo1x_decompress.c332
1 files changed, 332 insertions, 0 deletions
diff --git a/lib/lzo/lzo1x_decompress.c b/lib/lzo/lzo1x_decompress.c
new file mode 100644
index 0000000..09bdc8f
--- /dev/null
+++ b/lib/lzo/lzo1x_decompress.c
@@ -0,0 +1,332 @@
+/*
+ * LZO1X Decompressor from MiniLZO
+ *
+ * Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com>
+ *
+ * The full LZO package can be found at:
+ * http://www.oberhumer.com/opensource/lzo/
+ *
+ * Changed for kernel use by:
+ * Nitin Gupta <nitingupta910@gmail.com>
+ * Richard Purdie <rpurdie@openedhand.com>
+ */
+
+#include <common.h>
+#include <linux/lzo.h>
+#include <asm/byteorder.h>
+#include <asm/unaligned.h>
+#include "lzodefs.h"
+
+#define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x))
+#define HAVE_OP(x, op_end, op) ((size_t)(op_end - op) < (x))
+#define HAVE_LB(m_pos, out, op) (m_pos < out || m_pos >= op)
+
+#define COPY4(dst, src) \
+ put_unaligned(get_unaligned((const u32 *)(src)), (u32 *)(dst))
+
+static const unsigned char lzop_magic[] = {
+ 0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a
+};
+
+#define HEADER_HAS_FILTER 0x00000800L
+
+static inline const unsigned char *parse_header(const unsigned char *src)
+{
+ u8 level = 0;
+ u16 version;
+ int i;
+
+ /* read magic: 9 first bytes */
+ for (i = 0; i < ARRAY_SIZE(lzop_magic); i++) {
+ if (*src++ != lzop_magic[i])
+ return NULL;
+ }
+ /* get version (2bytes), skip library version (2),
+ * 'need to be extracted' version (2) and
+ * method (1) */
+ version = get_unaligned_be16(src);
+ src += 7;
+ if (version >= 0x0940)
+ level = *src++;
+ if (get_unaligned_be32(src) & HEADER_HAS_FILTER)
+ src += 4; /* filter info */
+
+ /* skip flags, mode and mtime_low */
+ src += 12;
+ if (version >= 0x0940)
+ src += 4; /* skip mtime_high */
+
+ i = *src++;
+ /* don't care about the file name, and skip checksum */
+ src += i + 4;
+
+ return src;
+}
+
+int lzop_decompress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len)
+{
+ unsigned char *start = dst;
+ const unsigned char *send = src + src_len;
+ u32 slen, dlen;
+ size_t tmp;
+ int r;
+
+ src = parse_header(src);
+ if (!src)
+ return LZO_E_ERROR;
+
+ while (src < send) {
+ /* read uncompressed block size */
+ dlen = get_unaligned_be32(src);
+ src += 4;
+
+ /* exit if last block */
+ if (dlen == 0) {
+ *dst_len = dst - start;
+ return LZO_E_OK;
+ }
+
+ /* read compressed block size, and skip block checksum info */
+ slen = get_unaligned_be32(src);
+ src += 8;
+
+ if (slen <= 0 || slen > dlen)
+ return LZO_E_ERROR;
+
+ /* decompress */
+ tmp = dlen;
+ r = lzo1x_decompress_safe((u8 *) src, slen, dst, &tmp);
+
+ if (r != LZO_E_OK)
+ return r;
+
+ if (dlen != tmp)
+ return LZO_E_ERROR;
+
+ src += slen;
+ dst += dlen;
+ }
+
+ return LZO_E_INPUT_OVERRUN;
+}
+
+int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
+ unsigned char *out, size_t *out_len)
+{
+ const unsigned char * const ip_end = in + in_len;
+ unsigned char * const op_end = out + *out_len;
+ const unsigned char *ip = in, *m_pos;
+ unsigned char *op = out;
+ size_t t;
+
+ *out_len = 0;
+
+ if (*ip > 17) {
+ t = *ip++ - 17;
+ if (t < 4)
+ goto match_next;
+ if (HAVE_OP(t, op_end, op))
+ goto output_overrun;
+ if (HAVE_IP(t + 1, ip_end, ip))
+ goto input_overrun;
+ do {
+ *op++ = *ip++;
+ } while (--t > 0);
+ goto first_literal_run;
+ }
+
+ while ((ip < ip_end)) {
+ t = *ip++;
+ if (t >= 16)
+ goto match;
+ if (t == 0) {
+ if (HAVE_IP(1, ip_end, ip))
+ goto input_overrun;
+ while (*ip == 0) {
+ t += 255;
+ ip++;
+ if (HAVE_IP(1, ip_end, ip))
+ goto input_overrun;
+ }
+ t += 15 + *ip++;
+ }
+ if (HAVE_OP(t + 3, op_end, op))
+ goto output_overrun;
+ if (HAVE_IP(t + 4, ip_end, ip))
+ goto input_overrun;
+
+ COPY4(op, ip);
+ op += 4;
+ ip += 4;
+ if (--t > 0) {
+ if (t >= 4) {
+ do {
+ COPY4(op, ip);
+ op += 4;
+ ip += 4;
+ t -= 4;
+ } while (t >= 4);
+ if (t > 0) {
+ do {
+ *op++ = *ip++;
+ } while (--t > 0);
+ }
+ } else {
+ do {
+ *op++ = *ip++;
+ } while (--t > 0);
+ }
+ }
+
+first_literal_run:
+ t = *ip++;
+ if (t >= 16)
+ goto match;
+ m_pos = op - (1 + M2_MAX_OFFSET);
+ m_pos -= t >> 2;
+ m_pos -= *ip++ << 2;
+
+ if (HAVE_LB(m_pos, out, op))
+ goto lookbehind_overrun;
+
+ if (HAVE_OP(3, op_end, op))
+ goto output_overrun;
+ *op++ = *m_pos++;
+ *op++ = *m_pos++;
+ *op++ = *m_pos;
+
+ goto match_done;
+
+ do {
+match:
+ if (t >= 64) {
+ m_pos = op - 1;
+ m_pos -= (t >> 2) & 7;
+ m_pos -= *ip++ << 3;
+ t = (t >> 5) - 1;
+ if (HAVE_LB(m_pos, out, op))
+ goto lookbehind_overrun;
+ if (HAVE_OP(t + 3 - 1, op_end, op))
+ goto output_overrun;
+ goto copy_match;
+ } else if (t >= 32) {
+ t &= 31;
+ if (t == 0) {
+ if (HAVE_IP(1, ip_end, ip))
+ goto input_overrun;
+ while (*ip == 0) {
+ t += 255;
+ ip++;
+ if (HAVE_IP(1, ip_end, ip))
+ goto input_overrun;
+ }
+ t += 31 + *ip++;
+ }
+ m_pos = op - 1;
+ m_pos -= get_unaligned_le16(ip) >> 2;
+ ip += 2;
+ } else if (t >= 16) {
+ m_pos = op;
+ m_pos -= (t & 8) << 11;
+
+ t &= 7;
+ if (t == 0) {
+ if (HAVE_IP(1, ip_end, ip))
+ goto input_overrun;
+ while (*ip == 0) {
+ t += 255;
+ ip++;
+ if (HAVE_IP(1, ip_end, ip))
+ goto input_overrun;
+ }
+ t += 7 + *ip++;
+ }
+ m_pos -= get_unaligned_le16(ip) >> 2;
+ ip += 2;
+ if (m_pos == op)
+ goto eof_found;
+ m_pos -= 0x4000;
+ } else {
+ m_pos = op - 1;
+ m_pos -= t >> 2;
+ m_pos -= *ip++ << 2;
+
+ if (HAVE_LB(m_pos, out, op))
+ goto lookbehind_overrun;
+ if (HAVE_OP(2, op_end, op))
+ goto output_overrun;
+
+ *op++ = *m_pos++;
+ *op++ = *m_pos;
+ goto match_done;
+ }
+
+ if (HAVE_LB(m_pos, out, op))
+ goto lookbehind_overrun;
+ if (HAVE_OP(t + 3 - 1, op_end, op))
+ goto output_overrun;
+
+ if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) {
+ COPY4(op, m_pos);
+ op += 4;
+ m_pos += 4;
+ t -= 4 - (3 - 1);
+ do {
+ COPY4(op, m_pos);
+ op += 4;
+ m_pos += 4;
+ t -= 4;
+ } while (t >= 4);
+ if (t > 0)
+ do {
+ *op++ = *m_pos++;
+ } while (--t > 0);
+ } else {
+copy_match:
+ *op++ = *m_pos++;
+ *op++ = *m_pos++;
+ do {
+ *op++ = *m_pos++;
+ } while (--t > 0);
+ }
+match_done:
+ t = ip[-2] & 3;
+ if (t == 0)
+ break;
+match_next:
+ if (HAVE_OP(t, op_end, op))
+ goto output_overrun;
+ if (HAVE_IP(t + 1, ip_end, ip))
+ goto input_overrun;
+
+ *op++ = *ip++;
+ if (t > 1) {
+ *op++ = *ip++;
+ if (t > 2)
+ *op++ = *ip++;
+ }
+
+ t = *ip++;
+ } while (ip < ip_end);
+ }
+
+ *out_len = op - out;
+ return LZO_E_EOF_NOT_FOUND;
+
+eof_found:
+ *out_len = op - out;
+ return (ip == ip_end ? LZO_E_OK :
+ (ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
+input_overrun:
+ *out_len = op - out;
+ return LZO_E_INPUT_OVERRUN;
+
+output_overrun:
+ *out_len = op - out;
+ return LZO_E_OUTPUT_OVERRUN;
+
+lookbehind_overrun:
+ *out_len = op - out;
+ return LZO_E_LOOKBEHIND_OVERRUN;
+}
generated by cgit v1.1 at 2024-11-23 11:57:44 +0000