+++ /dev/null
-/* inflate.c -- zlib interface to inflate modules
- * Copyright (C) 1995-2002 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
-
-#include "zutil.h"
-#include "infblock.h"
-
-struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
-
-typedef enum {
- METHOD, /* waiting for method byte */
- FLAG, /* waiting for flag byte */
- DICT4, /* four dictionary check bytes to go */
- DICT3, /* three dictionary check bytes to go */
- DICT2, /* two dictionary check bytes to go */
- DICT1, /* one dictionary check byte to go */
- DICT0, /* waiting for inflateSetDictionary */
- BLOCKS, /* decompressing blocks */
- CHECK4, /* four check bytes to go */
- CHECK3, /* three check bytes to go */
- CHECK2, /* two check bytes to go */
- CHECK1, /* one check byte to go */
- DONE, /* finished check, done */
- BAD} /* got an error--stay here */
-inflate_mode;
-
-/* inflate private state */
-struct internal_state {
-
- /* mode */
- inflate_mode mode; /* current inflate mode */
-
- /* mode dependent information */
- union {
- uInt method; /* if FLAGS, method byte */
- struct {
- uLong was; /* computed check value */
- uLong need; /* stream check value */
- } check; /* if CHECK, check values to compare */
- uInt marker; /* if BAD, inflateSync's marker bytes count */
- } sub; /* submode */
-
- /* mode independent information */
- int nowrap; /* flag for no wrapper */
- uInt wbits; /* log2(window size) (8..15, defaults to 15) */
- inflate_blocks_statef
- *blocks; /* current inflate_blocks state */
-
-};
-
-
-int ZEXPORT inflateReset(z)
-z_streamp z;
-{
- if (z == Z_NULL || z->state == Z_NULL)
- return Z_STREAM_ERROR;
- z->total_in = z->total_out = 0;
- z->msg = Z_NULL;
- z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
- inflate_blocks_reset(z->state->blocks, z, Z_NULL);
- Tracev((stderr, "inflate: reset\n"));
- return Z_OK;
-}
-
-
-int ZEXPORT inflateEnd(z)
-z_streamp z;
-{
- if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
- return Z_STREAM_ERROR;
- if (z->state->blocks != Z_NULL)
- inflate_blocks_free(z->state->blocks, z);
- ZFREE(z, z->state);
- z->state = Z_NULL;
- Tracev((stderr, "inflate: end\n"));
- return Z_OK;
-}
-
-
-int ZEXPORT inflateInit2_(z, w, version, stream_size)
-z_streamp z;
-int w;
-const char *version;
-int stream_size;
-{
- if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
- stream_size != sizeof(z_stream))
- return Z_VERSION_ERROR;
-
- /* initialize state */
- if (z == Z_NULL)
- return Z_STREAM_ERROR;
- z->msg = Z_NULL;
- if (z->zalloc == Z_NULL)
- {
- z->zalloc = zcalloc;
- z->opaque = (voidpf)0;
- }
- if (z->zfree == Z_NULL) z->zfree = zcfree;
- if ((z->state = (struct internal_state FAR *)
- ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
- return Z_MEM_ERROR;
- z->state->blocks = Z_NULL;
-
- /* handle undocumented nowrap option (no zlib header or check) */
- z->state->nowrap = 0;
- if (w < 0)
- {
- w = - w;
- z->state->nowrap = 1;
- }
-
- /* set window size */
- if (w < 8 || w > 15)
- {
- inflateEnd(z);
- return Z_STREAM_ERROR;
- }
- z->state->wbits = (uInt)w;
-
- /* create inflate_blocks state */
- if ((z->state->blocks =
- inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
- == Z_NULL)
- {
- inflateEnd(z);
- return Z_MEM_ERROR;
- }
- Tracev((stderr, "inflate: allocated\n"));
-
- /* reset state */
- inflateReset(z);
- return Z_OK;
-}
-
-
-int ZEXPORT inflateInit_(z, version, stream_size)
-z_streamp z;
-const char *version;
-int stream_size;
-{
- return inflateInit2_(z, DEF_WBITS, version, stream_size);
-}
-
-
-#define NEEDBYTE {if(z->avail_in==0)return r;r=f;}
-#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
-
-int ZEXPORT inflate(z, f)
-z_streamp z;
-int f;
-{
- int r;
- uInt b;
-
- if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
- return Z_STREAM_ERROR;
- f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
- r = Z_BUF_ERROR;
- while (1) switch (z->state->mode)
- {
- case METHOD:
- NEEDBYTE
- if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
- {
- z->state->mode = BAD;
- z->msg = (char*)"unknown compression method";
- z->state->sub.marker = 5; /* can't try inflateSync */
- break;
- }
- if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
- {
- z->state->mode = BAD;
- z->msg = (char*)"invalid window size";
- z->state->sub.marker = 5; /* can't try inflateSync */
- break;
- }
- z->state->mode = FLAG;
- case FLAG:
- NEEDBYTE
- b = NEXTBYTE;
- if (((z->state->sub.method << 8) + b) % 31)
- {
- z->state->mode = BAD;
- z->msg = (char*)"incorrect header check";
- z->state->sub.marker = 5; /* can't try inflateSync */
- break;
- }
- Tracev((stderr, "inflate: zlib header ok\n"));
- if (!(b & PRESET_DICT))
- {
- z->state->mode = BLOCKS;
- break;
- }
- z->state->mode = DICT4;
- case DICT4:
- NEEDBYTE
- z->state->sub.check.need = (uLong)NEXTBYTE << 24;
- z->state->mode = DICT3;
- case DICT3:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE << 16;
- z->state->mode = DICT2;
- case DICT2:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE << 8;
- z->state->mode = DICT1;
- case DICT1:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE;
- z->adler = z->state->sub.check.need;
- z->state->mode = DICT0;
- return Z_NEED_DICT;
- case DICT0:
- z->state->mode = BAD;
- z->msg = (char*)"need dictionary";
- z->state->sub.marker = 0; /* can try inflateSync */
- return Z_STREAM_ERROR;
- case BLOCKS:
- r = inflate_blocks(z->state->blocks, z, r);
- if (r == Z_DATA_ERROR)
- {
- z->state->mode = BAD;
- z->state->sub.marker = 0; /* can try inflateSync */
- break;
- }
- if (r == Z_OK)
- r = f;
- if (r != Z_STREAM_END)
- return r;
- r = f;
- inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
- if (z->state->nowrap)
- {
- z->state->mode = DONE;
- break;
- }
- z->state->mode = CHECK4;
- case CHECK4:
- NEEDBYTE
- z->state->sub.check.need = (uLong)NEXTBYTE << 24;
- z->state->mode = CHECK3;
- case CHECK3:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE << 16;
- z->state->mode = CHECK2;
- case CHECK2:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE << 8;
- z->state->mode = CHECK1;
- case CHECK1:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE;
-
- if (z->state->sub.check.was != z->state->sub.check.need)
- {
- z->state->mode = BAD;
- z->msg = (char*)"incorrect data check";
- z->state->sub.marker = 5; /* can't try inflateSync */
- break;
- }
- Tracev((stderr, "inflate: zlib check ok\n"));
- z->state->mode = DONE;
- case DONE:
- return Z_STREAM_END;
- case BAD:
- return Z_DATA_ERROR;
- default:
- return Z_STREAM_ERROR;
- }
-#ifdef NEED_DUMMY_RETURN
- return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
-#endif
-}
-
-
-int ZEXPORT inflateSetDictionary(z, dictionary, dictLength)
-z_streamp z;
-const Bytef *dictionary;
-uInt dictLength;
-{
- uInt length = dictLength;
-
- if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
- return Z_STREAM_ERROR;
-
- if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
- z->adler = 1L;
-
- if (length >= ((uInt)1<<z->state->wbits))
- {
- length = (1<<z->state->wbits)-1;
- dictionary += dictLength - length;
- }
- inflate_set_dictionary(z->state->blocks, dictionary, length);
- z->state->mode = BLOCKS;
- return Z_OK;
-}
-
-
-int ZEXPORT inflateSync(z)
-z_streamp z;
-{
- uInt n; /* number of bytes to look at */
- Bytef *p; /* pointer to bytes */
- uInt m; /* number of marker bytes found in a row */
- uLong r, w; /* temporaries to save total_in and total_out */
-
- /* set up */
- if (z == Z_NULL || z->state == Z_NULL)
- return Z_STREAM_ERROR;
- if (z->state->mode != BAD)
- {
- z->state->mode = BAD;
- z->state->sub.marker = 0;
- }
- if ((n = z->avail_in) == 0)
- return Z_BUF_ERROR;
- p = z->next_in;
- m = z->state->sub.marker;
-
- /* search */
- while (n && m < 4)
- {
- static const Byte mark[4] = {0, 0, 0xff, 0xff};
- if (*p == mark[m])
- m++;
- else if (*p)
- m = 0;
- else
- m = 4 - m;
- p++, n--;
- }
-
- /* restore */
- z->total_in += p - z->next_in;
- z->next_in = p;
- z->avail_in = n;
- z->state->sub.marker = m;
-
- /* return no joy or set up to restart on a new block */
- if (m != 4)
- return Z_DATA_ERROR;
- r = z->total_in; w = z->total_out;
- inflateReset(z);
- z->total_in = r; z->total_out = w;
- z->state->mode = BLOCKS;
- return Z_OK;
-}
-
-
-/* Returns true if inflate is currently at the end of a block generated
- * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
- * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
- * but removes the length bytes of the resulting empty stored block. When
- * decompressing, PPP checks that at the end of input packet, inflate is
- * waiting for these length bytes.
- */
-int ZEXPORT inflateSyncPoint(z)
-z_streamp z;
-{
- if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_NULL)
- return Z_STREAM_ERROR;
- return inflate_blocks_sync_point(z->state->blocks);
-}
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