815 lines
27 KiB
C
815 lines
27 KiB
C
/* inflate.c -- zlib decompression
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* Copyright (C) 1995-2005 Mark Adler
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* For conditions of distribution and use, see copyright notice in zlib.h
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*
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* Based on zlib 1.2.3 but modified for the Linux Kernel by
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* Richard Purdie <richard@openedhand.com>
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*
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* Changes mainly for static instead of dynamic memory allocation
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*
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*/
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#include <linux/zutil.h>
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#include "inftrees.h"
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#include "inflate.h"
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#include "inffast.h"
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#include "infutil.h"
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/* architecture-specific bits */
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#ifdef CONFIG_ZLIB_DFLTCC
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# include "../zlib_dfltcc/dfltcc_inflate.h"
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#else
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#define INFLATE_RESET_HOOK(strm) do {} while (0)
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#define INFLATE_TYPEDO_HOOK(strm, flush) do {} while (0)
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#define INFLATE_NEED_UPDATEWINDOW(strm) 1
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#define INFLATE_NEED_CHECKSUM(strm) 1
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#endif
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int zlib_inflate_workspacesize(void)
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{
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return sizeof(struct inflate_workspace);
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}
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int zlib_inflateReset(z_streamp strm)
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{
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struct inflate_state *state;
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if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
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state = (struct inflate_state *)strm->state;
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strm->total_in = strm->total_out = state->total = 0;
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strm->msg = NULL;
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strm->adler = 1; /* to support ill-conceived Java test suite */
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state->mode = HEAD;
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state->last = 0;
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state->havedict = 0;
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state->dmax = 32768U;
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state->hold = 0;
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state->bits = 0;
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state->lencode = state->distcode = state->next = state->codes;
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/* Initialise Window */
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state->wsize = 1U << state->wbits;
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state->write = 0;
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state->whave = 0;
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INFLATE_RESET_HOOK(strm);
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return Z_OK;
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}
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int zlib_inflateInit2(z_streamp strm, int windowBits)
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{
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struct inflate_state *state;
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if (strm == NULL) return Z_STREAM_ERROR;
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strm->msg = NULL; /* in case we return an error */
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state = &WS(strm)->inflate_state;
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strm->state = (struct internal_state *)state;
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if (windowBits < 0) {
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state->wrap = 0;
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windowBits = -windowBits;
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}
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else {
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state->wrap = (windowBits >> 4) + 1;
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}
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if (windowBits < 8 || windowBits > 15) {
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return Z_STREAM_ERROR;
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}
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state->wbits = (unsigned)windowBits;
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#ifdef CONFIG_ZLIB_DFLTCC
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/*
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* DFLTCC requires the window to be page aligned.
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* Thus, we overallocate and take the aligned portion of the buffer.
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*/
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state->window = PTR_ALIGN(&WS(strm)->working_window[0], PAGE_SIZE);
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#else
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state->window = &WS(strm)->working_window[0];
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#endif
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return zlib_inflateReset(strm);
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}
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/*
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Return state with length and distance decoding tables and index sizes set to
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fixed code decoding. This returns fixed tables from inffixed.h.
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*/
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static void zlib_fixedtables(struct inflate_state *state)
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{
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# include "inffixed.h"
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state->lencode = lenfix;
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state->lenbits = 9;
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state->distcode = distfix;
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state->distbits = 5;
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}
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/*
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Update the window with the last wsize (normally 32K) bytes written before
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returning. This is only called when a window is already in use, or when
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output has been written during this inflate call, but the end of the deflate
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stream has not been reached yet. It is also called to window dictionary data
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when a dictionary is loaded.
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Providing output buffers larger than 32K to inflate() should provide a speed
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advantage, since only the last 32K of output is copied to the sliding window
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upon return from inflate(), and since all distances after the first 32K of
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output will fall in the output data, making match copies simpler and faster.
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The advantage may be dependent on the size of the processor's data caches.
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*/
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static void zlib_updatewindow(z_streamp strm, unsigned out)
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{
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struct inflate_state *state;
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unsigned copy, dist;
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state = (struct inflate_state *)strm->state;
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/* copy state->wsize or less output bytes into the circular window */
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copy = out - strm->avail_out;
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if (copy >= state->wsize) {
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memcpy(state->window, strm->next_out - state->wsize, state->wsize);
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state->write = 0;
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state->whave = state->wsize;
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}
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else {
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dist = state->wsize - state->write;
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if (dist > copy) dist = copy;
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memcpy(state->window + state->write, strm->next_out - copy, dist);
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copy -= dist;
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if (copy) {
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memcpy(state->window, strm->next_out - copy, copy);
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state->write = copy;
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state->whave = state->wsize;
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}
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else {
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state->write += dist;
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if (state->write == state->wsize) state->write = 0;
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if (state->whave < state->wsize) state->whave += dist;
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}
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}
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}
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/*
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* At the end of a Deflate-compressed PPP packet, we expect to have seen
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* a `stored' block type value but not the (zero) length bytes.
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*/
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/*
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Returns true if inflate is currently at the end of a block generated by
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Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
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implementation to provide an additional safety check. PPP uses
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Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
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block. When decompressing, PPP checks that at the end of input packet,
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inflate is waiting for these length bytes.
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*/
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static int zlib_inflateSyncPacket(z_streamp strm)
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{
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struct inflate_state *state;
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if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
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state = (struct inflate_state *)strm->state;
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if (state->mode == STORED && state->bits == 0) {
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state->mode = TYPE;
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return Z_OK;
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}
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return Z_DATA_ERROR;
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}
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/* Macros for inflate(): */
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/* check function to use adler32() for zlib or crc32() for gzip */
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#define UPDATE(check, buf, len) zlib_adler32(check, buf, len)
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/* Load registers with state in inflate() for speed */
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#define LOAD() \
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do { \
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put = strm->next_out; \
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left = strm->avail_out; \
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next = strm->next_in; \
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have = strm->avail_in; \
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hold = state->hold; \
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bits = state->bits; \
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} while (0)
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/* Restore state from registers in inflate() */
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#define RESTORE() \
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do { \
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strm->next_out = put; \
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strm->avail_out = left; \
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strm->next_in = next; \
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strm->avail_in = have; \
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state->hold = hold; \
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state->bits = bits; \
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} while (0)
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/* Clear the input bit accumulator */
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#define INITBITS() \
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do { \
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hold = 0; \
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bits = 0; \
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} while (0)
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/* Get a byte of input into the bit accumulator, or return from inflate()
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if there is no input available. */
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#define PULLBYTE() \
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do { \
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if (have == 0) goto inf_leave; \
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have--; \
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hold += (unsigned long)(*next++) << bits; \
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bits += 8; \
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} while (0)
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/* Assure that there are at least n bits in the bit accumulator. If there is
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not enough available input to do that, then return from inflate(). */
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#define NEEDBITS(n) \
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do { \
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while (bits < (unsigned)(n)) \
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PULLBYTE(); \
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} while (0)
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/* Return the low n bits of the bit accumulator (n < 16) */
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#define BITS(n) \
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((unsigned)hold & ((1U << (n)) - 1))
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/* Remove n bits from the bit accumulator */
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#define DROPBITS(n) \
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do { \
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hold >>= (n); \
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bits -= (unsigned)(n); \
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} while (0)
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/* Remove zero to seven bits as needed to go to a byte boundary */
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#define BYTEBITS() \
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do { \
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hold >>= bits & 7; \
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bits -= bits & 7; \
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} while (0)
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/*
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inflate() uses a state machine to process as much input data and generate as
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much output data as possible before returning. The state machine is
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structured roughly as follows:
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for (;;) switch (state) {
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...
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case STATEn:
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if (not enough input data or output space to make progress)
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return;
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... make progress ...
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state = STATEm;
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break;
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...
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}
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so when inflate() is called again, the same case is attempted again, and
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if the appropriate resources are provided, the machine proceeds to the
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next state. The NEEDBITS() macro is usually the way the state evaluates
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whether it can proceed or should return. NEEDBITS() does the return if
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the requested bits are not available. The typical use of the BITS macros
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is:
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NEEDBITS(n);
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... do something with BITS(n) ...
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DROPBITS(n);
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where NEEDBITS(n) either returns from inflate() if there isn't enough
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input left to load n bits into the accumulator, or it continues. BITS(n)
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gives the low n bits in the accumulator. When done, DROPBITS(n) drops
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the low n bits off the accumulator. INITBITS() clears the accumulator
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and sets the number of available bits to zero. BYTEBITS() discards just
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enough bits to put the accumulator on a byte boundary. After BYTEBITS()
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and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
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NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
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if there is no input available. The decoding of variable length codes uses
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PULLBYTE() directly in order to pull just enough bytes to decode the next
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code, and no more.
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Some states loop until they get enough input, making sure that enough
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state information is maintained to continue the loop where it left off
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if NEEDBITS() returns in the loop. For example, want, need, and keep
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would all have to actually be part of the saved state in case NEEDBITS()
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returns:
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case STATEw:
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while (want < need) {
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NEEDBITS(n);
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keep[want++] = BITS(n);
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DROPBITS(n);
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}
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state = STATEx;
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case STATEx:
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As shown above, if the next state is also the next case, then the break
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is omitted.
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A state may also return if there is not enough output space available to
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complete that state. Those states are copying stored data, writing a
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literal byte, and copying a matching string.
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When returning, a "goto inf_leave" is used to update the total counters,
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update the check value, and determine whether any progress has been made
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during that inflate() call in order to return the proper return code.
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Progress is defined as a change in either strm->avail_in or strm->avail_out.
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When there is a window, goto inf_leave will update the window with the last
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output written. If a goto inf_leave occurs in the middle of decompression
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and there is no window currently, goto inf_leave will create one and copy
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output to the window for the next call of inflate().
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In this implementation, the flush parameter of inflate() only affects the
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return code (per zlib.h). inflate() always writes as much as possible to
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strm->next_out, given the space available and the provided input--the effect
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documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
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the allocation of and copying into a sliding window until necessary, which
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provides the effect documented in zlib.h for Z_FINISH when the entire input
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stream available. So the only thing the flush parameter actually does is:
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when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
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will return Z_BUF_ERROR if it has not reached the end of the stream.
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*/
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int zlib_inflate(z_streamp strm, int flush)
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{
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struct inflate_state *state;
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const unsigned char *next; /* next input */
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unsigned char *put; /* next output */
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unsigned have, left; /* available input and output */
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unsigned long hold; /* bit buffer */
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unsigned bits; /* bits in bit buffer */
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unsigned in, out; /* save starting available input and output */
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unsigned copy; /* number of stored or match bytes to copy */
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unsigned char *from; /* where to copy match bytes from */
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code this; /* current decoding table entry */
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code last; /* parent table entry */
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unsigned len; /* length to copy for repeats, bits to drop */
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int ret; /* return code */
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static const unsigned short order[19] = /* permutation of code lengths */
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{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
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/* Do not check for strm->next_out == NULL here as ppc zImage
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inflates to strm->next_out = 0 */
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if (strm == NULL || strm->state == NULL ||
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(strm->next_in == NULL && strm->avail_in != 0))
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return Z_STREAM_ERROR;
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state = (struct inflate_state *)strm->state;
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if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
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LOAD();
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in = have;
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out = left;
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ret = Z_OK;
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for (;;)
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switch (state->mode) {
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case HEAD:
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if (state->wrap == 0) {
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state->mode = TYPEDO;
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break;
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}
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NEEDBITS(16);
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if (
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((BITS(8) << 8) + (hold >> 8)) % 31) {
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strm->msg = (char *)"incorrect header check";
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state->mode = BAD;
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break;
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}
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if (BITS(4) != Z_DEFLATED) {
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strm->msg = (char *)"unknown compression method";
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state->mode = BAD;
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break;
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}
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DROPBITS(4);
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len = BITS(4) + 8;
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if (len > state->wbits) {
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strm->msg = (char *)"invalid window size";
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state->mode = BAD;
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break;
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}
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state->dmax = 1U << len;
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strm->adler = state->check = zlib_adler32(0L, NULL, 0);
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state->mode = hold & 0x200 ? DICTID : TYPE;
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INITBITS();
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break;
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case DICTID:
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NEEDBITS(32);
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strm->adler = state->check = REVERSE(hold);
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INITBITS();
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state->mode = DICT;
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fallthrough;
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case DICT:
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if (state->havedict == 0) {
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RESTORE();
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return Z_NEED_DICT;
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}
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strm->adler = state->check = zlib_adler32(0L, NULL, 0);
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state->mode = TYPE;
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fallthrough;
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case TYPE:
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if (flush == Z_BLOCK) goto inf_leave;
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fallthrough;
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case TYPEDO:
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INFLATE_TYPEDO_HOOK(strm, flush);
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if (state->last) {
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BYTEBITS();
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state->mode = CHECK;
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break;
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}
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NEEDBITS(3);
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state->last = BITS(1);
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DROPBITS(1);
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switch (BITS(2)) {
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case 0: /* stored block */
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state->mode = STORED;
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break;
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case 1: /* fixed block */
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zlib_fixedtables(state);
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state->mode = LEN; /* decode codes */
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break;
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case 2: /* dynamic block */
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state->mode = TABLE;
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break;
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case 3:
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strm->msg = (char *)"invalid block type";
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state->mode = BAD;
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}
|
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DROPBITS(2);
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break;
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case STORED:
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BYTEBITS(); /* go to byte boundary */
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NEEDBITS(32);
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if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
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strm->msg = (char *)"invalid stored block lengths";
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state->mode = BAD;
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break;
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}
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state->length = (unsigned)hold & 0xffff;
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INITBITS();
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state->mode = COPY;
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fallthrough;
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case COPY:
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copy = state->length;
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if (copy) {
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if (copy > have) copy = have;
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if (copy > left) copy = left;
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if (copy == 0) goto inf_leave;
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memcpy(put, next, copy);
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have -= copy;
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next += copy;
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left -= copy;
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put += copy;
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state->length -= copy;
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break;
|
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}
|
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state->mode = TYPE;
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break;
|
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case TABLE:
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NEEDBITS(14);
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state->nlen = BITS(5) + 257;
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DROPBITS(5);
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state->ndist = BITS(5) + 1;
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DROPBITS(5);
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state->ncode = BITS(4) + 4;
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DROPBITS(4);
|
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#ifndef PKZIP_BUG_WORKAROUND
|
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if (state->nlen > 286 || state->ndist > 30) {
|
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strm->msg = (char *)"too many length or distance symbols";
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state->mode = BAD;
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break;
|
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}
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#endif
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state->have = 0;
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state->mode = LENLENS;
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fallthrough;
|
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case LENLENS:
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while (state->have < state->ncode) {
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NEEDBITS(3);
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state->lens[order[state->have++]] = (unsigned short)BITS(3);
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DROPBITS(3);
|
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}
|
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while (state->have < 19)
|
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state->lens[order[state->have++]] = 0;
|
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state->next = state->codes;
|
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state->lencode = (code const *)(state->next);
|
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state->lenbits = 7;
|
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ret = zlib_inflate_table(CODES, state->lens, 19, &(state->next),
|
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&(state->lenbits), state->work);
|
|
if (ret) {
|
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strm->msg = (char *)"invalid code lengths set";
|
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state->mode = BAD;
|
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break;
|
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}
|
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state->have = 0;
|
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state->mode = CODELENS;
|
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fallthrough;
|
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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;
|
|
fallthrough;
|
|
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;
|
|
fallthrough;
|
|
case LENEXT:
|
|
if (state->extra) {
|
|
NEEDBITS(state->extra);
|
|
state->length += BITS(state->extra);
|
|
DROPBITS(state->extra);
|
|
}
|
|
state->mode = DIST;
|
|
fallthrough;
|
|
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;
|
|
fallthrough;
|
|
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;
|
|
fallthrough;
|
|
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 (INFLATE_NEED_CHECKSUM(strm) && 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;
|
|
fallthrough;
|
|
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 (INFLATE_NEED_UPDATEWINDOW(strm) &&
|
|
(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 (INFLATE_NEED_CHECKSUM(strm) && 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 (flush == Z_PACKET_FLUSH && ret == Z_OK &&
|
|
strm->avail_out != 0 && strm->avail_in == 0)
|
|
return zlib_inflateSyncPacket(strm);
|
|
|
|
if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
|
|
ret = Z_BUF_ERROR;
|
|
|
|
return ret;
|
|
}
|
|
|
|
int zlib_inflateEnd(z_streamp strm)
|
|
{
|
|
if (strm == NULL || strm->state == NULL)
|
|
return Z_STREAM_ERROR;
|
|
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 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)
|
|
{
|
|
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 = (unsigned char*)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;
|
|
}
|