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814 lines
27 KiB
814 lines
27 KiB
/* 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 <[email protected]> |
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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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|
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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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|
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/* architecture-specific bits */ |
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#ifdef CONFIG_ZLIB_DFLTCC |
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# include "../zlib_dfltcc/dfltcc.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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|
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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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|
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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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|
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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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|
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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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|
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INFLATE_RESET_HOOK(strm); |
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return Z_OK; |
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} |
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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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|
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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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|
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state = &WS(strm)->inflate_state; |
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strm->state = (struct internal_state *)state; |
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|
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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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|
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return zlib_inflateReset(strm); |
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} |
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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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|
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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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|
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state = (struct inflate_state *)strm->state; |
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|
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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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/* |
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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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|
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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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|
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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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|
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/* Macros for inflate(): */ |
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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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/* |
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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state = (struct inflate_state *)strm->state; |
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|
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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); |
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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: |
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while (state->have < state->nlen + state->ndist) { |
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for (;;) { |
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this = state->lencode[BITS(state->lenbits)]; |
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if ((unsigned)(this.bits) <= bits) break; |
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PULLBYTE(); |
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} |
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if (this.val < 16) { |
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NEEDBITS(this.bits); |
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DROPBITS(this.bits); |
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state->lens[state->have++] = this.val; |
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} |
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else { |
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if (this.val == 16) { |
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NEEDBITS(this.bits + 2); |
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DROPBITS(this.bits); |
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if (state->have == 0) { |
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strm->msg = (char *)"invalid bit length repeat"; |
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state->mode = BAD; |
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break; |
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} |
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len = state->lens[state->have - 1]; |
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copy = 3 + BITS(2); |
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DROPBITS(2); |
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} |
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else if (this.val == 17) { |
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NEEDBITS(this.bits + 3); |
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DROPBITS(this.bits); |
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len = 0; |
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copy = 3 + BITS(3); |
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DROPBITS(3); |
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} |
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else { |
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NEEDBITS(this.bits + 7); |
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DROPBITS(this.bits); |
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len = 0; |
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copy = 11 + BITS(7); |
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DROPBITS(7); |
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} |
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if (state->have + copy > state->nlen + state->ndist) { |
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strm->msg = (char *)"invalid bit length repeat"; |
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state->mode = BAD; |
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break; |
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} |
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while (copy--) |
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state->lens[state->have++] = (unsigned short)len; |
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} |
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} |
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|
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/* handle error breaks in while */ |
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if (state->mode == BAD) break; |
|
|
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/* build code tables */ |
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state->next = state->codes; |
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state->lencode = (code const *)(state->next); |
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state->lenbits = 9; |
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ret = zlib_inflate_table(LENS, state->lens, state->nlen, &(state->next), |
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&(state->lenbits), state->work); |
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if (ret) { |
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strm->msg = (char *)"invalid literal/lengths set"; |
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state->mode = BAD; |
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break; |
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} |
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state->distcode = (code const *)(state->next); |
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state->distbits = 6; |
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ret = zlib_inflate_table(DISTS, state->lens + state->nlen, state->ndist, |
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&(state->next), &(state->distbits), state->work); |
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if (ret) { |
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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; |
|
}
|
|
|