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-rw-r--r--lib/zlib_inflate/inflate_sync.c148
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);
+}