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/* inflate.c -- zlib interface to inflate modules
* 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 "infutil.h"
int zlib_inflate_workspacesize(void)
{
return sizeof(struct inflate_workspace);
}
int zlib_inflateReset(
z_streamp z
)
{
if (z == NULL || z->state == NULL || z->workspace == NULL)
return Z_STREAM_ERROR;
z->total_in = z->total_out = 0;
z->msg = NULL;
z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
zlib_inflate_blocks_reset(z->state->blocks, z, NULL);
return Z_OK;
}
int zlib_inflateEnd(
z_streamp z
)
{
if (z == NULL || z->state == NULL || z->workspace == NULL)
return Z_STREAM_ERROR;
if (z->state->blocks != NULL)
zlib_inflate_blocks_free(z->state->blocks, z);
z->state = NULL;
return Z_OK;
}
int zlib_inflateInit2_(
z_streamp z,
int w,
const char *version,
int stream_size
)
{
if (version == NULL || version[0] != ZLIB_VERSION[0] ||
stream_size != sizeof(z_stream) || z->workspace == NULL)
return Z_VERSION_ERROR;
/* initialize state */
z->msg = NULL;
z->state = &WS(z)->internal_state;
z->state->blocks = 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)
{
zlib_inflateEnd(z);
return Z_STREAM_ERROR;
}
z->state->wbits = (uInt)w;
/* create inflate_blocks state */
if ((z->state->blocks =
zlib_inflate_blocks_new(z, z->state->nowrap ? NULL : zlib_adler32, (uInt)1 << w))
== NULL)
{
zlib_inflateEnd(z);
return Z_MEM_ERROR;
}
/* reset state */
zlib_inflateReset(z);
return Z_OK;
}
/*
* At the end of a Deflate-compressed PPP packet, we expect to have seen
* a `stored' block type value but not the (zero) length bytes.
*/
static int zlib_inflate_packet_flush(inflate_blocks_statef *s)
{
if (s->mode != LENS)
return Z_DATA_ERROR;
s->mode = TYPE;
return Z_OK;
}
int zlib_inflateInit_(
z_streamp z,
const char *version,
int stream_size
)
{
return zlib_inflateInit2_(z, DEF_WBITS, version, stream_size);
}
#undef NEEDBYTE
#undef NEXTBYTE
#define NEEDBYTE {if(z->avail_in==0)goto empty;r=trv;}
#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
int zlib_inflate(
z_streamp z,
int f
)
{
int r, trv;
uInt b;
if (z == NULL || z->state == NULL || z->next_in == NULL)
return Z_STREAM_ERROR;
trv = 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 = I_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 = I_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 = I_BAD;
z->msg = (char*)"incorrect header check";
z->state->sub.marker = 5; /* can't try inflateSync */
break;
}
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 = I_BAD;
z->msg = (char*)"need dictionary";
z->state->sub.marker = 0; /* can try inflateSync */
return Z_STREAM_ERROR;
case BLOCKS:
r = zlib_inflate_blocks(z->state->blocks, z, r);
if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
r = zlib_inflate_packet_flush(z->state->blocks);
if (r == Z_DATA_ERROR)
{
z->state->mode = I_BAD;
z->state->sub.marker = 0; /* can try inflateSync */
break;
}
if (r == Z_OK)
r = trv;
if (r != Z_STREAM_END)
return r;
r = trv;
zlib_inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
if (z->state->nowrap)
{
z->state->mode = I_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 = I_BAD;
z->msg = (char*)"incorrect data check";
z->state->sub.marker = 5; /* can't try inflateSync */
break;
}
z->state->mode = I_DONE;
case I_DONE:
return Z_STREAM_END;
case I_BAD:
return Z_DATA_ERROR;
default:
return Z_STREAM_ERROR;
}
empty:
if (f != Z_PACKET_FLUSH)
return r;
z->state->mode = I_BAD;
z->msg = (char *)"need more for packet flush";
z->state->sub.marker = 0; /* can try inflateSync */
return Z_DATA_ERROR;
}
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