/* 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" | |
#define DONE INFLATE_DONE | |
#define BAD INFLATE_BAD | |
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 */ | |
}; | |
ZEXPORT(int) 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; | |
} | |
ZEXPORT(int) 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; | |
} | |
ZEXPORT(int) 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; | |
} | |
#undef NEEDBYTE | |
#define NEEDBYTE {if(z->avail_in==0)return r;r=f;} | |
#undef NEXTBYTE | |
#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) | |
ZEXPORT(int) 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 | |
} | |