Merge to Fedora kernel-2.6.18-1.2224_FC5 patched with stable patch-2.6.18.1-vs2.0...
[linux-2.6.git] / lib / zlib_inflate / inflate.c
index 31b9e90..fceb97c 100644 (file)
-/* 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 
+/* inflate.c -- zlib decompression
+ * Copyright (C) 1995-2005 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Based on zlib 1.2.3 but modified for the Linux Kernel by
+ * Richard Purdie <richard@openedhand.com>
+ *
+ * Changes mainly for static instead of dynamic memory allocation
+ *
  */
 
 #include <linux/zutil.h>
-#include "infblock.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
 #include "infutil.h"
 
 int zlib_inflate_workspacesize(void)
 {
-  return sizeof(struct inflate_workspace);
+    return sizeof(struct inflate_workspace);
 }
 
+int zlib_inflateReset(z_streamp strm)
+{
+    struct inflate_state *state;
+
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+    strm->total_in = strm->total_out = state->total = 0;
+    strm->msg = NULL;
+    strm->adler = 1;        /* to support ill-conceived Java test suite */
+    state->mode = HEAD;
+    state->last = 0;
+    state->havedict = 0;
+    state->dmax = 32768U;
+    state->hold = 0;
+    state->bits = 0;
+    state->lencode = state->distcode = state->next = state->codes;
 
-int zlib_inflateReset(
-       z_streamp z
-)
+    /* Initialise Window */
+    state->wsize = 1U << state->wbits;
+    state->write = 0;
+    state->whave = 0;
+
+    return Z_OK;
+}
+
+#if 0
+int zlib_inflatePrime(z_streamp strm, int bits, int value)
 {
-  if (z == NULL || z->state == NULL || z->workspace == NULL)
-    return Z_STREAM_ERROR;
-  z->total_in = z->total_out = 0;
-  z->msg = NULL;
-  z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
-  zlib_inflate_blocks_reset(z->state->blocks, z, NULL);
-  return Z_OK;
+    struct inflate_state *state;
+
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+    if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
+    value &= (1L << bits) - 1;
+    state->hold += value << state->bits;
+    state->bits += bits;
+    return Z_OK;
 }
+#endif
+
+int zlib_inflateInit2(z_streamp strm, int windowBits)
+{
+    struct inflate_state *state;
+
+    if (strm == NULL) return Z_STREAM_ERROR;
+    strm->msg = NULL;                 /* in case we return an error */
+
+    state = &WS(strm)->inflate_state;
+    strm->state = (struct internal_state *)state;
+
+    if (windowBits < 0) {
+        state->wrap = 0;
+        windowBits = -windowBits;
+    }
+    else {
+        state->wrap = (windowBits >> 4) + 1;
+    }
+    if (windowBits < 8 || windowBits > 15) {
+        return Z_STREAM_ERROR;
+    }
+    state->wbits = (unsigned)windowBits;
+    state->window = &WS(strm)->working_window[0];
 
+    return zlib_inflateReset(strm);
+}
 
-int zlib_inflateEnd(
-       z_streamp z
-)
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  This returns fixed tables from inffixed.h.
+ */
+static void zlib_fixedtables(struct inflate_state *state)
 {
-  if (z == NULL || z->state == NULL || z->workspace == NULL)
-    return Z_STREAM_ERROR;
-  if (z->state->blocks != NULL)
-    zlib_inflate_blocks_free(z->state->blocks, z);
-  z->state = NULL;
-  return Z_OK;
+#   include "inffixed.h"
+    state->lencode = lenfix;
+    state->lenbits = 9;
+    state->distcode = distfix;
+    state->distbits = 5;
 }
 
 
-int zlib_inflateInit2_(
-       z_streamp z,
-       int w,
-       const char *version,
-       int stream_size
-)
+/*
+   Update the window with the last wsize (normally 32K) bytes written before
+   returning. This is only called when a window is already in use, or when
+   output has been written during this inflate call, but the end of the deflate
+   stream has not been reached yet. It is also called to window dictionary data
+   when a dictionary is loaded.
+
+   Providing output buffers larger than 32K to inflate() should provide a speed
+   advantage, since only the last 32K of output is copied to the sliding window
+   upon return from inflate(), and since all distances after the first 32K of
+   output will fall in the output data, making match copies simpler and faster.
+   The advantage may be dependent on the size of the processor's data caches.
+ */
+static void zlib_updatewindow(z_streamp strm, unsigned out)
 {
-  if (version == NULL || version[0] != ZLIB_VERSION[0] ||
-      stream_size != sizeof(z_stream) || z->workspace == NULL)
-      return Z_VERSION_ERROR;
-
-  /* initialize state */
-  z->msg = NULL;
-  z->state = &WS(z)->internal_state;
-  z->state->blocks = 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 ? NULL : zlib_adler32, (uInt)1 << w))
-      == NULL)
-  {
-    zlib_inflateEnd(z);
-    return Z_MEM_ERROR;
-  }
-
-  /* reset state */
-  zlib_inflateReset(z);
-  return Z_OK;
+    struct inflate_state *state;
+    unsigned copy, dist;
+
+    state = (struct inflate_state *)strm->state;
+
+    /* copy state->wsize or less output bytes into the circular window */
+    copy = out - strm->avail_out;
+    if (copy >= state->wsize) {
+        memcpy(state->window, strm->next_out - state->wsize, state->wsize);
+        state->write = 0;
+        state->whave = state->wsize;
+    }
+    else {
+        dist = state->wsize - state->write;
+        if (dist > copy) dist = copy;
+        memcpy(state->window + state->write, strm->next_out - copy, dist);
+        copy -= dist;
+        if (copy) {
+            memcpy(state->window, strm->next_out - copy, copy);
+            state->write = copy;
+            state->whave = state->wsize;
+        }
+        else {
+            state->write += dist;
+            if (state->write == state->wsize) state->write = 0;
+            if (state->whave < state->wsize) state->whave += dist;
+        }
+    }
 }
 
 
@@ -91,157 +150,767 @@ int zlib_inflateInit2_(
  * 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)
+/*
+   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.
+ */
+static int zlib_inflateSyncPacket(z_streamp strm)
 {
-    if (s->mode != LENS)
-       return Z_DATA_ERROR;
-    s->mode = TYPE;
+    struct inflate_state *state;
+
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+
+    if (state->mode == STORED && state->bits == 0) {
+       state->mode = TYPE;
+        return Z_OK;
+    }
+    return Z_DATA_ERROR;
+}
+
+/* Macros for inflate(): */
+
+/* check function to use adler32() for zlib or crc32() for gzip */
+#define UPDATE(check, buf, len) zlib_adler32(check, buf, len)
+
+/* Load registers with state in inflate() for speed */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state->hold; \
+        bits = state->bits; \
+    } while (0)
+
+/* Restore state from registers in inflate() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state->hold = hold; \
+        state->bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflate()
+   if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        if (have == 0) goto inf_leave; \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflate(). */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/* Reverse the bytes in a 32-bit value */
+#define REVERSE(q) \
+    ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
+     (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
+
+/*
+   inflate() uses a state machine to process as much input data and generate as
+   much output data as possible before returning.  The state machine is
+   structured roughly as follows:
+
+    for (;;) switch (state) {
+    ...
+    case STATEn:
+        if (not enough input data or output space to make progress)
+            return;
+        ... make progress ...
+        state = STATEm;
+        break;
+    ...
+    }
+
+   so when inflate() is called again, the same case is attempted again, and
+   if the appropriate resources are provided, the machine proceeds to the
+   next state.  The NEEDBITS() macro is usually the way the state evaluates
+   whether it can proceed or should return.  NEEDBITS() does the return if
+   the requested bits are not available.  The typical use of the BITS macros
+   is:
+
+        NEEDBITS(n);
+        ... do something with BITS(n) ...
+        DROPBITS(n);
+
+   where NEEDBITS(n) either returns from inflate() if there isn't enough
+   input left to load n bits into the accumulator, or it continues.  BITS(n)
+   gives the low n bits in the accumulator.  When done, DROPBITS(n) drops
+   the low n bits off the accumulator.  INITBITS() clears the accumulator
+   and sets the number of available bits to zero.  BYTEBITS() discards just
+   enough bits to put the accumulator on a byte boundary.  After BYTEBITS()
+   and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+
+   NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
+   if there is no input available.  The decoding of variable length codes uses
+   PULLBYTE() directly in order to pull just enough bytes to decode the next
+   code, and no more.
+
+   Some states loop until they get enough input, making sure that enough
+   state information is maintained to continue the loop where it left off
+   if NEEDBITS() returns in the loop.  For example, want, need, and keep
+   would all have to actually be part of the saved state in case NEEDBITS()
+   returns:
+
+    case STATEw:
+        while (want < need) {
+            NEEDBITS(n);
+            keep[want++] = BITS(n);
+            DROPBITS(n);
+        }
+        state = STATEx;
+    case STATEx:
+
+   As shown above, if the next state is also the next case, then the break
+   is omitted.
+
+   A state may also return if there is not enough output space available to
+   complete that state.  Those states are copying stored data, writing a
+   literal byte, and copying a matching string.
+
+   When returning, a "goto inf_leave" is used to update the total counters,
+   update the check value, and determine whether any progress has been made
+   during that inflate() call in order to return the proper return code.
+   Progress is defined as a change in either strm->avail_in or strm->avail_out.
+   When there is a window, goto inf_leave will update the window with the last
+   output written.  If a goto inf_leave occurs in the middle of decompression
+   and there is no window currently, goto inf_leave will create one and copy
+   output to the window for the next call of inflate().
+
+   In this implementation, the flush parameter of inflate() only affects the
+   return code (per zlib.h).  inflate() always writes as much as possible to
+   strm->next_out, given the space available and the provided input--the effect
+   documented in zlib.h of Z_SYNC_FLUSH.  Furthermore, inflate() always defers
+   the allocation of and copying into a sliding window until necessary, which
+   provides the effect documented in zlib.h for Z_FINISH when the entire input
+   stream available.  So the only thing the flush parameter actually does is:
+   when flush is set to Z_FINISH, inflate() cannot return Z_OK.  Instead it
+   will return Z_BUF_ERROR if it has not reached the end of the stream.
+ */
+
+int zlib_inflate(z_streamp strm, int flush)
+{
+    struct inflate_state *state;
+    unsigned char *next;    /* next input */
+    unsigned char *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned in, out;           /* save starting available input and output */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char *from;    /* where to copy match bytes from */
+    code this;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    /* Do not check for strm->next_out == NULL here as ppc zImage
+       inflates to strm->next_out = 0 */
+
+    if (strm == NULL || strm->state == NULL ||
+        (strm->next_in == NULL && strm->avail_in != 0))
+        return Z_STREAM_ERROR;
+
+    state = (struct inflate_state *)strm->state;
+
+    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
+    LOAD();
+    in = have;
+    out = left;
+    ret = Z_OK;
+    for (;;)
+        switch (state->mode) {
+        case HEAD:
+            if (state->wrap == 0) {
+                state->mode = TYPEDO;
+                break;
+            }
+            NEEDBITS(16);
+            if (
+                ((BITS(8) << 8) + (hold >> 8)) % 31) {
+                strm->msg = (char *)"incorrect header check";
+                state->mode = BAD;
+                break;
+            }
+            if (BITS(4) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state->mode = BAD;
+                break;
+            }
+            DROPBITS(4);
+            len = BITS(4) + 8;
+            if (len > state->wbits) {
+                strm->msg = (char *)"invalid window size";
+                state->mode = BAD;
+                break;
+            }
+            state->dmax = 1U << len;
+            strm->adler = state->check = zlib_adler32(0L, NULL, 0);
+            state->mode = hold & 0x200 ? DICTID : TYPE;
+            INITBITS();
+            break;
+        case DICTID:
+            NEEDBITS(32);
+            strm->adler = state->check = REVERSE(hold);
+            INITBITS();
+            state->mode = DICT;
+        case DICT:
+            if (state->havedict == 0) {
+                RESTORE();
+                return Z_NEED_DICT;
+            }
+            strm->adler = state->check = zlib_adler32(0L, NULL, 0);
+            state->mode = TYPE;
+        case TYPE:
+            if (flush == Z_BLOCK) goto inf_leave;
+        case TYPEDO:
+            if (state->last) {
+                BYTEBITS();
+                state->mode = CHECK;
+                break;
+            }
+            NEEDBITS(3);
+            state->last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                state->mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                zlib_fixedtables(state);
+                state->mode = LEN;              /* decode codes */
+                break;
+            case 2:                             /* dynamic block */
+                state->mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state->mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+        case STORED:
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state->mode = BAD;
+                break;
+            }
+            state->length = (unsigned)hold & 0xffff;
+            INITBITS();
+            state->mode = COPY;
+        case COPY:
+            copy = state->length;
+            if (copy) {
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                if (copy == 0) goto inf_leave;
+                memcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state->length -= copy;
+                break;
+            }
+            state->mode = TYPE;
+            break;
+        case TABLE:
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state->nlen > 286 || state->ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            state->have = 0;
+            state->mode = LENLENS;
+        case LENLENS:
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            state->lencode = (code const *)(state->next);
+            state->lenbits = 7;
+            ret = zlib_inflate_table(CODES, state->lens, 19, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->have = 0;
+            state->mode = CODELENS;
+        case CODELENS:
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    this = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (this.val < 16) {
+                    NEEDBITS(this.bits);
+                    DROPBITS(this.bits);
+                    state->lens[state->have++] = this.val;
+                }
+                else {
+                    if (this.val == 16) {
+                        NEEDBITS(this.bits + 2);
+                        DROPBITS(this.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state->mode = BAD;
+                            break;
+                        }
+                        len = state->lens[state->have - 1];
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (this.val == 17) {
+                        NEEDBITS(this.bits + 3);
+                        DROPBITS(this.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(this.bits + 7);
+                        DROPBITS(this.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state->mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state->mode == BAD) break;
+
+            /* build code tables */
+            state->next = state->codes;
+            state->lencode = (code const *)(state->next);
+            state->lenbits = 9;
+            ret = zlib_inflate_table(LENS, state->lens, state->nlen, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->distcode = (code const *)(state->next);
+            state->distbits = 6;
+            ret = zlib_inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+                            &(state->next), &(state->distbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state->mode = BAD;
+                break;
+            }
+            state->mode = LEN;
+        case LEN:
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                inflate_fast(strm, out);
+                LOAD();
+                break;
+            }
+            for (;;) {
+                this = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(this.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (this.op && (this.op & 0xf0) == 0) {
+                last = this;
+                for (;;) {
+                    this = state->lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(this.bits);
+            state->length = (unsigned)this.val;
+            if ((int)(this.op) == 0) {
+                state->mode = LIT;
+                break;
+            }
+            if (this.op & 32) {
+                state->mode = TYPE;
+                break;
+            }
+            if (this.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state->mode = BAD;
+                break;
+            }
+            state->extra = (unsigned)(this.op) & 15;
+            state->mode = LENEXT;
+        case LENEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->length += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+            state->mode = DIST;
+        case DIST:
+            for (;;) {
+                this = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(this.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((this.op & 0xf0) == 0) {
+                last = this;
+                for (;;) {
+                    this = state->distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(this.bits);
+            if (this.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+            state->offset = (unsigned)this.val;
+            state->extra = (unsigned)(this.op) & 15;
+            state->mode = DISTEXT;
+        case DISTEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->offset += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+#ifdef INFLATE_STRICT
+            if (state->offset > state->dmax) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            if (state->offset > state->whave + out - left) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+            state->mode = MATCH;
+        case MATCH:
+            if (left == 0) goto inf_leave;
+            copy = out - left;
+            if (state->offset > copy) {         /* copy from window */
+                copy = state->offset - copy;
+                if (copy > state->write) {
+                    copy -= state->write;
+                    from = state->window + (state->wsize - copy);
+                }
+                else
+                    from = state->window + (state->write - copy);
+                if (copy > state->length) copy = state->length;
+            }
+            else {                              /* copy from output */
+                from = put - state->offset;
+                copy = state->length;
+            }
+            if (copy > left) copy = left;
+            left -= copy;
+            state->length -= copy;
+            do {
+                *put++ = *from++;
+            } while (--copy);
+            if (state->length == 0) state->mode = LEN;
+            break;
+        case LIT:
+            if (left == 0) goto inf_leave;
+            *put++ = (unsigned char)(state->length);
+            left--;
+            state->mode = LEN;
+            break;
+        case CHECK:
+            if (state->wrap) {
+                NEEDBITS(32);
+                out -= left;
+                strm->total_out += out;
+                state->total += out;
+                if (out)
+                    strm->adler = state->check =
+                        UPDATE(state->check, put - out, out);
+                out = left;
+                if ((
+                     REVERSE(hold)) != state->check) {
+                    strm->msg = (char *)"incorrect data check";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+            }
+            state->mode = DONE;
+        case DONE:
+            ret = Z_STREAM_END;
+            goto inf_leave;
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+        case MEM:
+            return Z_MEM_ERROR;
+        case SYNC:
+        default:
+            return Z_STREAM_ERROR;
+        }
+
+    /*
+       Return from inflate(), updating the total counts and the check value.
+       If there was no progress during the inflate() call, return a buffer
+       error.  Call zlib_updatewindow() to create and/or update the window state.
+     */
+  inf_leave:
+    RESTORE();
+    if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
+        zlib_updatewindow(strm, out);
+
+    in -= strm->avail_in;
+    out -= strm->avail_out;
+    strm->total_in += in;
+    strm->total_out += out;
+    state->total += out;
+    if (state->wrap && out)
+        strm->adler = state->check =
+            UPDATE(state->check, strm->next_out - out, out);
+
+    strm->data_type = state->bits + (state->last ? 64 : 0) +
+                      (state->mode == TYPE ? 128 : 0);
+    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
+        ret = Z_BUF_ERROR;
+
+    if (flush == Z_PACKET_FLUSH && ret == Z_OK &&
+            (strm->avail_out != 0 || strm->avail_in == 0))
+               return zlib_inflateSyncPacket(strm);
+    return ret;
+}
+
+int zlib_inflateEnd(z_streamp strm)
+{
+    if (strm == NULL || strm->state == NULL)
+        return Z_STREAM_ERROR;
     return Z_OK;
 }
 
+#if 0
+int zlib_inflateSetDictionary(z_streamp strm, const Byte *dictionary,
+        uInt dictLength)
+{
+    struct inflate_state *state;
+    unsigned long id;
+
+    /* check state */
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+    if (state->wrap != 0 && state->mode != DICT)
+        return Z_STREAM_ERROR;
+
+    /* check for correct dictionary id */
+    if (state->mode == DICT) {
+        id = zlib_adler32(0L, NULL, 0);
+        id = zlib_adler32(id, dictionary, dictLength);
+        if (id != state->check)
+            return Z_DATA_ERROR;
+    }
+
+    /* copy dictionary to window */
+    zlib_updatewindow(strm, strm->avail_out);
 
-int zlib_inflateInit_(
-       z_streamp z,
-       const char *version,
-       int stream_size
-)
+    if (dictLength > state->wsize) {
+        memcpy(state->window, dictionary + dictLength - state->wsize,
+                state->wsize);
+        state->whave = state->wsize;
+    }
+    else {
+        memcpy(state->window + state->wsize - dictLength, dictionary,
+                dictLength);
+        state->whave = dictLength;
+    }
+    state->havedict = 1;
+    return Z_OK;
+}
+#endif
+
+#if 0
+/*
+   Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff.  Return when found
+   or when out of input.  When called, *have is the number of pattern bytes
+   found in order so far, in 0..3.  On return *have is updated to the new
+   state.  If on return *have equals four, then the pattern was found and the
+   return value is how many bytes were read including the last byte of the
+   pattern.  If *have is less than four, then the pattern has not been found
+   yet and the return value is len.  In the latter case, zlib_syncsearch() can be
+   called again with more data and the *have state.  *have is initialized to
+   zero for the first call.
+ */
+static unsigned zlib_syncsearch(unsigned *have, unsigned char *buf,
+        unsigned len)
 {
-  return zlib_inflateInit2_(z, DEF_WBITS, version, stream_size);
+    unsigned got;
+    unsigned next;
+
+    got = *have;
+    next = 0;
+    while (next < len && got < 4) {
+        if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
+            got++;
+        else if (buf[next])
+            got = 0;
+        else
+            got = 4 - got;
+        next++;
+    }
+    *have = got;
+    return next;
 }
+#endif
 
-#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++)
+#if 0
+int zlib_inflateSync(z_streamp strm)
+{
+    unsigned len;               /* number of bytes to look at or looked at */
+    unsigned long in, out;      /* temporary to save total_in and total_out */
+    unsigned char buf[4];       /* to restore bit buffer to byte string */
+    struct inflate_state *state;
+
+    /* check parameters */
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+    if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
+
+    /* if first time, start search in bit buffer */
+    if (state->mode != SYNC) {
+        state->mode = SYNC;
+        state->hold <<= state->bits & 7;
+        state->bits -= state->bits & 7;
+        len = 0;
+        while (state->bits >= 8) {
+            buf[len++] = (unsigned char)(state->hold);
+            state->hold >>= 8;
+            state->bits -= 8;
+        }
+        state->have = 0;
+        zlib_syncsearch(&(state->have), buf, len);
+    }
+
+    /* search available input */
+    len = zlib_syncsearch(&(state->have), strm->next_in, strm->avail_in);
+    strm->avail_in -= len;
+    strm->next_in += len;
+    strm->total_in += len;
+
+    /* return no joy or set up to restart inflate() on a new block */
+    if (state->have != 4) return Z_DATA_ERROR;
+    in = strm->total_in;  out = strm->total_out;
+    zlib_inflateReset(strm);
+    strm->total_in = in;  strm->total_out = out;
+    state->mode = TYPE;
+    return Z_OK;
+}
+#endif
 
-int zlib_inflate(
-       z_streamp z,
-       int f
-)
+/*
+ * 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 but this should always be the case. The state must
+ * be waiting on the start of a block (i.e. mode == TYPE or HEAD).  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)
 {
-  int r, trv;
-  uInt b;
-
-  if (z == NULL || z->state == NULL || z->next_in == 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;
+    struct inflate_state *state = (struct inflate_state *)z->state;
+    Byte *saved_no = z->next_out;
+    uInt saved_ao = z->avail_out;
+
+    if (state->mode != TYPE && state->mode != HEAD)
+       return Z_DATA_ERROR;
+
+    /* Setup some variables to allow misuse of updateWindow */
+    z->avail_out = 0;
+    z->next_out = z->next_in + z->avail_in;
+
+    zlib_updatewindow(z, z->avail_in);
+
+    /* Restore saved variables */
+    z->avail_out = saved_ao;
+    z->next_out = saved_no;
+
+    z->adler = state->check =
+        UPDATE(state->check, z->next_in, z->avail_in);
+
+    z->total_out += z->avail_in;
+    z->total_in += z->avail_in;
+    z->next_in += z->avail_in;
+    state->total += z->avail_in;
+    z->avail_in = 0;
+
+    return Z_OK;
 }