1 files changed, 148 insertions, 0 deletions
diff --git a/lib/zlib_inflate/inflate_sync.c b/lib/zlib_inflate/inflate_sync.c
new file mode 100644
index 000000000000..e07bdb21f55c
--- /dev/null
+++ b/lib/zlib_inflate/inflate_sync.c
@@ -0,0 +1,148 @@
+/* inflate.c -- zlib interface to inflate modules
+ * Copyright (C) 1995-1998 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include <linux/zutil.h>
+#include "infblock.h"
+#include "infutil.h"
+
+int zlib_inflateSync(
+	z_streamp z
+)
+{
+  uInt n;       /* number of bytes to look at */
+  Byte *p;      /* pointer to bytes */
+  uInt m;       /* number of marker bytes found in a row */
+  uLong r, w;   /* temporaries to save total_in and total_out */
+
+  /* set up */
+  if (z == NULL || z->state == NULL)
+    return Z_STREAM_ERROR;
+  if (z->state->mode != I_BAD)
+  {
+    z->state->mode = I_BAD;
+    z->state->sub.marker = 0;
+  }
+  if ((n = z->avail_in) == 0)
+    return Z_BUF_ERROR;
+  p = z->next_in;
+  m = z->state->sub.marker;
+
+  /* search */
+  while (n && m < 4)
+  {
+    static const Byte mark[4] = {0, 0, 0xff, 0xff};
+    if (*p == mark[m])
+      m++;
+    else if (*p)
+      m = 0;
+    else
+      m = 4 - m;
+    p++, n--;
+  }
+
+  /* restore */
+  z->total_in += p - z->next_in;
+  z->next_in = p;
+  z->avail_in = n;
+  z->state->sub.marker = m;
+
+  /* return no joy or set up to restart on a new block */
+  if (m != 4)
+    return Z_DATA_ERROR;
+  r = z->total_in;  w = z->total_out;
+  zlib_inflateReset(z);
+  z->total_in = r;  z->total_out = w;
+  z->state->mode = BLOCKS;
+  return Z_OK;
+}
+
+
+/* Returns true if inflate is currently at the end of a block generated
+ * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+ * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
+ * but removes the length bytes of the resulting empty stored block. When
+ * decompressing, PPP checks that at the end of input packet, inflate is
+ * waiting for these length bytes.
+ */
+int zlib_inflateSyncPoint(
+	z_streamp z
+)
+{
+  if (z == NULL || z->state == NULL || z->state->blocks == NULL)
+    return Z_STREAM_ERROR;
+  return zlib_inflate_blocks_sync_point(z->state->blocks);
+}
+
+/*
+ * This subroutine adds the data at next_in/avail_in to the output history
+ * without performing any output.  The output buffer must be "caught up";
+ * i.e. no pending output (hence s->read equals s->write), and the state must
+ * be BLOCKS (i.e. we should be willing to see the start of a series of
+ * BLOCKS).  On exit, the output will also be caught up, and the checksum
+ * will have been updated if need be.
+ */
+static int zlib_inflate_addhistory(inflate_blocks_statef *s,
+				      z_stream              *z)
+{
+    uLong b;              /* bit buffer */  /* NOT USED HERE */
+    uInt k;               /* bits in bit buffer */ /* NOT USED HERE */
+    uInt t;               /* temporary storage */
+    Byte *p;              /* input data pointer */
+    uInt n;               /* bytes available there */
+    Byte *q;              /* output window write pointer */
+    uInt m;               /* bytes to end of window or read pointer */
+
+    if (s->read != s->write)
+	return Z_STREAM_ERROR;
+    if (s->mode != TYPE)
+	return Z_DATA_ERROR;
+
+    /* we're ready to rock */
+    LOAD
+    /* while there is input ready, copy to output buffer, moving
+     * pointers as needed.
+     */
+    while (n) {
+	t = n;  /* how many to do */
+	/* is there room until end of buffer? */
+	if (t > m) t = m;
+	/* update check information */
+	if (s->checkfn != NULL)
+	    s->check = (*s->checkfn)(s->check, q, t);
+	memcpy(q, p, t);
+	q += t;
+	p += t;
+	n -= t;
+	z->total_out += t;
+	s->read = q;    /* drag read pointer forward */
+/*      WWRAP  */ 	/* expand WWRAP macro by hand to handle s->read */
+	if (q == s->end) {
+	    s->read = q = s->window;
+	    m = WAVAIL;
+	}
+    }
+    UPDATE
+    return Z_OK;
+}
+
+
+/*
+ * This subroutine adds the data at next_in/avail_in to the output history
+ * without performing any output.  The output buffer must be "caught up";
+ * i.e. no pending output (hence s->read equals s->write), and the state must
+ * be BLOCKS (i.e. we should be willing to see the start of a series of
+ * BLOCKS).  On exit, the output will also be caught up, and the checksum
+ * will have been updated if need be.
+ */
+
+int zlib_inflateIncomp(
+	z_stream *z
+
+)
+{
+    if (z->state->mode != BLOCKS)
+	return Z_DATA_ERROR;
+    return zlib_inflate_addhistory(z->state->blocks, z);
+}