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-rw-r--r--lib/zlib_inflate/infblock.c361
1 files changed, 361 insertions, 0 deletions
diff --git a/lib/zlib_inflate/infblock.c b/lib/zlib_inflate/infblock.c
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+++ b/lib/zlib_inflate/infblock.c
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+/* infblock.c -- interpret and process block types to last block
+ * Copyright (C) 1995-1998 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include <linux/zutil.h>
+#include "infblock.h"
+#include "inftrees.h"
+#include "infcodes.h"
+#include "infutil.h"
+
+struct inflate_codes_state;
+
+/* simplify the use of the inflate_huft type with some defines */
+#define exop word.what.Exop
+#define bits word.what.Bits
+
+/* Table for deflate from PKZIP's appnote.txt. */
+static const uInt border[] = { /* Order of the bit length code lengths */
+ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+/*
+ Notes beyond the 1.93a appnote.txt:
+
+ 1. Distance pointers never point before the beginning of the output
+ stream.
+ 2. Distance pointers can point back across blocks, up to 32k away.
+ 3. There is an implied maximum of 7 bits for the bit length table and
+ 15 bits for the actual data.
+ 4. If only one code exists, then it is encoded using one bit. (Zero
+ would be more efficient, but perhaps a little confusing.) If two
+ codes exist, they are coded using one bit each (0 and 1).
+ 5. There is no way of sending zero distance codes--a dummy must be
+ sent if there are none. (History: a pre 2.0 version of PKZIP would
+ store blocks with no distance codes, but this was discovered to be
+ too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
+ zero distance codes, which is sent as one code of zero bits in
+ length.
+ 6. There are up to 286 literal/length codes. Code 256 represents the
+ end-of-block. Note however that the static length tree defines
+ 288 codes just to fill out the Huffman codes. Codes 286 and 287
+ cannot be used though, since there is no length base or extra bits
+ defined for them. Similarily, there are up to 30 distance codes.
+ However, static trees define 32 codes (all 5 bits) to fill out the
+ Huffman codes, but the last two had better not show up in the data.
+ 7. Unzip can check dynamic Huffman blocks for complete code sets.
+ The exception is that a single code would not be complete (see #4).
+ 8. The five bits following the block type is really the number of
+ literal codes sent minus 257.
+ 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
+ (1+6+6). Therefore, to output three times the length, you output
+ three codes (1+1+1), whereas to output four times the same length,
+ you only need two codes (1+3). Hmm.
+ 10. In the tree reconstruction algorithm, Code = Code + Increment
+ only if BitLength(i) is not zero. (Pretty obvious.)
+ 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
+ 12. Note: length code 284 can represent 227-258, but length code 285
+ really is 258. The last length deserves its own, short code
+ since it gets used a lot in very redundant files. The length
+ 258 is special since 258 - 3 (the min match length) is 255.
+ 13. The literal/length and distance code bit lengths are read as a
+ single stream of lengths. It is possible (and advantageous) for
+ a repeat code (16, 17, or 18) to go across the boundary between
+ the two sets of lengths.
+ */
+
+
+void zlib_inflate_blocks_reset(
+ inflate_blocks_statef *s,
+ z_streamp z,
+ uLong *c
+)
+{
+ if (c != NULL)
+ *c = s->check;
+ if (s->mode == CODES)
+ zlib_inflate_codes_free(s->sub.decode.codes, z);
+ s->mode = TYPE;
+ s->bitk = 0;
+ s->bitb = 0;
+ s->read = s->write = s->window;
+ if (s->checkfn != NULL)
+ z->adler = s->check = (*s->checkfn)(0L, NULL, 0);
+}
+
+inflate_blocks_statef *zlib_inflate_blocks_new(
+ z_streamp z,
+ check_func c,
+ uInt w
+)
+{
+ inflate_blocks_statef *s;
+
+ s = &WS(z)->working_blocks_state;
+ s->hufts = WS(z)->working_hufts;
+ s->window = WS(z)->working_window;
+ s->end = s->window + w;
+ s->checkfn = c;
+ s->mode = TYPE;
+ zlib_inflate_blocks_reset(s, z, NULL);
+ return s;
+}
+
+
+int zlib_inflate_blocks(
+ inflate_blocks_statef *s,
+ z_streamp z,
+ int r
+)
+{
+ uInt t; /* temporary storage */
+ uLong b; /* bit buffer */
+ uInt k; /* bits in bit buffer */
+ Byte *p; /* input data pointer */
+ uInt n; /* bytes available there */
+ Byte *q; /* output window write pointer */
+ uInt m; /* bytes to end of window or read pointer */
+
+ /* copy input/output information to locals (UPDATE macro restores) */
+ LOAD
+
+ /* process input based on current state */
+ while (1) switch (s->mode)
+ {
+ case TYPE:
+ NEEDBITS(3)
+ t = (uInt)b & 7;
+ s->last = t & 1;
+ switch (t >> 1)
+ {
+ case 0: /* stored */
+ DUMPBITS(3)
+ t = k & 7; /* go to byte boundary */
+ DUMPBITS(t)
+ s->mode = LENS; /* get length of stored block */
+ break;
+ case 1: /* fixed */
+ {
+ uInt bl, bd;
+ inflate_huft *tl, *td;
+
+ zlib_inflate_trees_fixed(&bl, &bd, &tl, &td, s->hufts, z);
+ s->sub.decode.codes = zlib_inflate_codes_new(bl, bd, tl, td, z);
+ if (s->sub.decode.codes == NULL)
+ {
+ r = Z_MEM_ERROR;
+ LEAVE
+ }
+ }
+ DUMPBITS(3)
+ s->mode = CODES;
+ break;
+ case 2: /* dynamic */
+ DUMPBITS(3)
+ s->mode = TABLE;
+ break;
+ case 3: /* illegal */
+ DUMPBITS(3)
+ s->mode = B_BAD;
+ z->msg = (char*)"invalid block type";
+ r = Z_DATA_ERROR;
+ LEAVE
+ }
+ break;
+ case LENS:
+ NEEDBITS(32)
+ if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
+ {
+ s->mode = B_BAD;
+ z->msg = (char*)"invalid stored block lengths";
+ r = Z_DATA_ERROR;
+ LEAVE
+ }
+ s->sub.left = (uInt)b & 0xffff;
+ b = k = 0; /* dump bits */
+ s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
+ break;
+ case STORED:
+ if (n == 0)
+ LEAVE
+ NEEDOUT
+ t = s->sub.left;
+ if (t > n) t = n;
+ if (t > m) t = m;
+ memcpy(q, p, t);
+ p += t; n -= t;
+ q += t; m -= t;
+ if ((s->sub.left -= t) != 0)
+ break;
+ s->mode = s->last ? DRY : TYPE;
+ break;
+ case TABLE:
+ NEEDBITS(14)
+ s->sub.trees.table = t = (uInt)b & 0x3fff;
+#ifndef PKZIP_BUG_WORKAROUND
+ if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
+ {
+ s->mode = B_BAD;
+ z->msg = (char*)"too many length or distance symbols";
+ r = Z_DATA_ERROR;
+ LEAVE
+ }
+#endif
+ {
+ s->sub.trees.blens = WS(z)->working_blens;
+ }
+ DUMPBITS(14)
+ s->sub.trees.index = 0;
+ s->mode = BTREE;
+ case BTREE:
+ while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
+ {
+ NEEDBITS(3)
+ s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
+ DUMPBITS(3)
+ }
+ while (s->sub.trees.index < 19)
+ s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
+ s->sub.trees.bb = 7;
+ t = zlib_inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
+ &s->sub.trees.tb, s->hufts, z);
+ if (t != Z_OK)
+ {
+ r = t;
+ if (r == Z_DATA_ERROR)
+ s->mode = B_BAD;
+ LEAVE
+ }
+ s->sub.trees.index = 0;
+ s->mode = DTREE;
+ case DTREE:
+ while (t = s->sub.trees.table,
+ s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
+ {
+ inflate_huft *h;
+ uInt i, j, c;
+
+ t = s->sub.trees.bb;
+ NEEDBITS(t)
+ h = s->sub.trees.tb + ((uInt)b & zlib_inflate_mask[t]);
+ t = h->bits;
+ c = h->base;
+ if (c < 16)
+ {
+ DUMPBITS(t)
+ s->sub.trees.blens[s->sub.trees.index++] = c;
+ }
+ else /* c == 16..18 */
+ {
+ i = c == 18 ? 7 : c - 14;
+ j = c == 18 ? 11 : 3;
+ NEEDBITS(t + i)
+ DUMPBITS(t)
+ j += (uInt)b & zlib_inflate_mask[i];
+ DUMPBITS(i)
+ i = s->sub.trees.index;
+ t = s->sub.trees.table;
+ if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
+ (c == 16 && i < 1))
+ {
+ s->mode = B_BAD;
+ z->msg = (char*)"invalid bit length repeat";
+ r = Z_DATA_ERROR;
+ LEAVE
+ }
+ c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
+ do {
+ s->sub.trees.blens[i++] = c;
+ } while (--j);
+ s->sub.trees.index = i;
+ }
+ }
+ s->sub.trees.tb = NULL;
+ {
+ uInt bl, bd;
+ inflate_huft *tl, *td;
+ inflate_codes_statef *c;
+
+ bl = 9; /* must be <= 9 for lookahead assumptions */
+ bd = 6; /* must be <= 9 for lookahead assumptions */
+ t = s->sub.trees.table;
+ t = zlib_inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
+ s->sub.trees.blens, &bl, &bd, &tl, &td,
+ s->hufts, z);
+ if (t != Z_OK)
+ {
+ if (t == (uInt)Z_DATA_ERROR)
+ s->mode = B_BAD;
+ r = t;
+ LEAVE
+ }
+ if ((c = zlib_inflate_codes_new(bl, bd, tl, td, z)) == NULL)
+ {
+ r = Z_MEM_ERROR;
+ LEAVE
+ }
+ s->sub.decode.codes = c;
+ }
+ s->mode = CODES;
+ case CODES:
+ UPDATE
+ if ((r = zlib_inflate_codes(s, z, r)) != Z_STREAM_END)
+ return zlib_inflate_flush(s, z, r);
+ r = Z_OK;
+ zlib_inflate_codes_free(s->sub.decode.codes, z);
+ LOAD
+ if (!s->last)
+ {
+ s->mode = TYPE;
+ break;
+ }
+ s->mode = DRY;
+ case DRY:
+ FLUSH
+ if (s->read != s->write)
+ LEAVE
+ s->mode = B_DONE;
+ case B_DONE:
+ r = Z_STREAM_END;
+ LEAVE
+ case B_BAD:
+ r = Z_DATA_ERROR;
+ LEAVE
+ default:
+ r = Z_STREAM_ERROR;
+ LEAVE
+ }
+}
+
+
+int zlib_inflate_blocks_free(
+ inflate_blocks_statef *s,
+ z_streamp z
+)
+{
+ zlib_inflate_blocks_reset(s, z, NULL);
+ return Z_OK;
+}
+
+
+void zlib_inflate_set_dictionary(
+ inflate_blocks_statef *s,
+ const Byte *d,
+ uInt n
+)
+{
+ memcpy(s->window, d, n);
+ s->read = s->write = s->window + n;
+}
+
+
+/* Returns true if inflate is currently at the end of a block generated
+ * by Z_SYNC_FLUSH or Z_FULL_FLUSH.
+ * IN assertion: s != NULL
+ */
+int zlib_inflate_blocks_sync_point(
+ inflate_blocks_statef *s
+)
+{
+ return s->mode == LENS;
+}
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