patch-2.4.20 linux-2.4.20/lib/zlib_inflate/inflate.c

• Lines: 383
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/lib/zlib_inflate/inflate.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/lib/zlib_inflate/inflate.c linux-2.4.20/lib/zlib_inflate/inflate.c
@@ -0,0 +1,382 @@
+/* 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/module.h>
+#include <linux/zutil.h>
+#include "infblock.h"
+#include "infutil.h"
+
+int ZEXPORT zlib_inflate_workspacesize(void)
+{
+  return sizeof(struct inflate_workspace);
+}
+
+
+int ZEXPORT zlib_inflateReset(z)
+z_streamp z;
+{
+  if (z == Z_NULL || z->state == Z_NULL || z->workspace == Z_NULL)
+    return Z_STREAM_ERROR;
+  z->total_in = z->total_out = 0;
+  z->msg = Z_NULL;
+  z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
+  zlib_inflate_blocks_reset(z->state->blocks, z, Z_NULL);
+  return Z_OK;
+}
+
+
+int ZEXPORT zlib_inflateEnd(z)
+z_streamp z;
+{
+  if (z == Z_NULL || z->state == Z_NULL || z->workspace == Z_NULL)
+    return Z_STREAM_ERROR;
+  if (z->state->blocks != Z_NULL)
+    zlib_inflate_blocks_free(z->state->blocks, z);
+  z->state = Z_NULL;
+  return Z_OK;
+}
+
+
+int ZEXPORT zlib_inflateInit2_(z, w, version, stream_size)
+z_streamp z;
+int w;
+const char *version;
+int stream_size;
+{
+  if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+      stream_size != sizeof(z_stream) || z->workspace == Z_NULL)
+      return Z_VERSION_ERROR;
+
+  /* initialize state */
+  if (z == Z_NULL)
+    return Z_STREAM_ERROR;
+  z->msg = Z_NULL;
+  z->state = &WS(z)->internal_state;
+  z->state->blocks = Z_NULL;
+
+  /* handle undocumented nowrap option (no zlib header or check) */
+  z->state->nowrap = 0;
+  if (w < 0)
+  {
+    w = - w;
+    z->state->nowrap = 1;
+  }
+
+  /* set window size */
+  if (w < 8 || w > 15)
+  {
+    zlib_inflateEnd(z);
+    return Z_STREAM_ERROR;
+  }
+  z->state->wbits = (uInt)w;
+
+  /* create inflate_blocks state */
+  if ((z->state->blocks =
+      zlib_inflate_blocks_new(z, z->state->nowrap ? Z_NULL : zlib_adler32, (uInt)1 << w))
+      == Z_NULL)
+  {
+    zlib_inflateEnd(z);
+    return Z_MEM_ERROR;
+  }
+
+  /* reset state */
+  zlib_inflateReset(z);
+  return Z_OK;
+}
+
+
+/*
+ * At the end of a Deflate-compressed PPP packet, we expect to have seen
+ * a `stored' block type value but not the (zero) length bytes.
+ */
+static int zlib_inflate_packet_flush(inflate_blocks_statef *s)
+{
+    if (s->mode != LENS)
+	return Z_DATA_ERROR;
+    s->mode = TYPE;
+    return Z_OK;
+}
+
+
+int ZEXPORT zlib_inflateInit_(z, version, stream_size)
+z_streamp z;
+const char *version;
+int stream_size;
+{
+  return zlib_inflateInit2_(z, DEF_WBITS, version, stream_size);
+}
+
+#undef NEEDBYTE
+#undef NEXTBYTE
+#define NEEDBYTE {if(z->avail_in==0)goto empty;r=trv;}
+#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
+
+int ZEXPORT zlib_inflate(z, f)
+z_streamp z;
+int f;
+{
+  int r, trv;
+  uInt b;
+
+  if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
+    return Z_STREAM_ERROR;
+  trv = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
+  r = Z_BUF_ERROR;
+  while (1) switch (z->state->mode)
+  {
+    case METHOD:
+      NEEDBYTE
+      if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
+      {
+        z->state->mode = I_BAD;
+        z->msg = (char*)"unknown compression method";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
+      {
+        z->state->mode = I_BAD;
+        z->msg = (char*)"invalid window size";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      z->state->mode = FLAG;
+    case FLAG:
+      NEEDBYTE
+      b = NEXTBYTE;
+      if (((z->state->sub.method << 8) + b) % 31)
+      {
+        z->state->mode = I_BAD;
+        z->msg = (char*)"incorrect header check";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      if (!(b & PRESET_DICT))
+      {
+        z->state->mode = BLOCKS;
+        break;
+      }
+      z->state->mode = DICT4;
+    case DICT4:
+      NEEDBYTE
+      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
+      z->state->mode = DICT3;
+    case DICT3:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
+      z->state->mode = DICT2;
+    case DICT2:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
+      z->state->mode = DICT1;
+    case DICT1:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE;
+      z->adler = z->state->sub.check.need;
+      z->state->mode = DICT0;
+      return Z_NEED_DICT;
+    case DICT0:
+      z->state->mode = I_BAD;
+      z->msg = (char*)"need dictionary";
+      z->state->sub.marker = 0;       /* can try inflateSync */
+      return Z_STREAM_ERROR;
+    case BLOCKS:
+      r = zlib_inflate_blocks(z->state->blocks, z, r);
+      if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
+	  r = zlib_inflate_packet_flush(z->state->blocks);
+      if (r == Z_DATA_ERROR)
+      {
+        z->state->mode = I_BAD;
+        z->state->sub.marker = 0;       /* can try inflateSync */
+        break;
+      }
+      if (r == Z_OK)
+        r = trv;
+      if (r != Z_STREAM_END)
+        return r;
+      r = trv;
+      zlib_inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
+      if (z->state->nowrap)
+      {
+        z->state->mode = I_DONE;
+        break;
+      }
+      z->state->mode = CHECK4;
+    case CHECK4:
+      NEEDBYTE
+      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
+      z->state->mode = CHECK3;
+    case CHECK3:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
+      z->state->mode = CHECK2;
+    case CHECK2:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
+      z->state->mode = CHECK1;
+    case CHECK1:
+      NEEDBYTE
+      z->state->sub.check.need += (uLong)NEXTBYTE;
+
+      if (z->state->sub.check.was != z->state->sub.check.need)
+      {
+        z->state->mode = I_BAD;
+        z->msg = (char*)"incorrect data check";
+        z->state->sub.marker = 5;       /* can't try inflateSync */
+        break;
+      }
+      z->state->mode = I_DONE;
+    case I_DONE:
+      return Z_STREAM_END;
+    case I_BAD:
+      return Z_DATA_ERROR;
+    default:
+      return Z_STREAM_ERROR;
+  }
+ empty:
+  if (f != Z_PACKET_FLUSH)
+    return r;
+  z->state->mode = I_BAD;
+  z->msg = (char *)"need more for packet flush";
+  z->state->sub.marker = 0;       /* can try inflateSync */
+  return Z_DATA_ERROR;
+}
+
+
+int ZEXPORT zlib_inflateSync(z)
+z_streamp z;
+{
+  uInt n;       /* number of bytes to look at */
+  Bytef *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 == Z_NULL || z->state == Z_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 ZEXPORT zlib_inflateSyncPoint(z)
+z_streamp z;
+{
+  if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_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 */
+    Bytef *p;             /* input data pointer */
+    uInt n;               /* bytes available there */
+    Bytef *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 != Z_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 ZEXPORT zlib_inflateIncomp(z)
+z_stream *z;
+{
+    if (z->state->mode != BLOCKS)
+	return Z_DATA_ERROR;
+    return zlib_inflate_addhistory(z->state->blocks, z);
+}