]>
git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - lib/zlib_inflate/inflate.c
1 /* inflate.c -- zlib interface to inflate modules
2 * Copyright (C) 1995-1998 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
6 #include <linux/zutil.h>
10 int zlib_inflate_workspacesize(void)
12 return sizeof(struct inflate_workspace
);
16 int zlib_inflateReset(
20 if (z
== NULL
|| z
->state
== NULL
|| z
->workspace
== NULL
)
21 return Z_STREAM_ERROR
;
22 z
->total_in
= z
->total_out
= 0;
24 z
->state
->mode
= z
->state
->nowrap
? BLOCKS
: METHOD
;
25 zlib_inflate_blocks_reset(z
->state
->blocks
, z
, NULL
);
34 if (z
== NULL
|| z
->state
== NULL
|| z
->workspace
== NULL
)
35 return Z_STREAM_ERROR
;
36 if (z
->state
->blocks
!= NULL
)
37 zlib_inflate_blocks_free(z
->state
->blocks
, z
);
43 int zlib_inflateInit2_(
50 if (version
== NULL
|| version
[0] != ZLIB_VERSION
[0] ||
51 stream_size
!= sizeof(z_stream
) || z
->workspace
== NULL
)
52 return Z_VERSION_ERROR
;
54 /* initialize state */
56 z
->state
= &WS(z
)->internal_state
;
57 z
->state
->blocks
= NULL
;
59 /* handle undocumented nowrap option (no zlib header or check) */
71 return Z_STREAM_ERROR
;
73 z
->state
->wbits
= (uInt
)w
;
75 /* create inflate_blocks state */
76 if ((z
->state
->blocks
=
77 zlib_inflate_blocks_new(z
, z
->state
->nowrap
? NULL
: zlib_adler32
, (uInt
)1 << w
))
91 * At the end of a Deflate-compressed PPP packet, we expect to have seen
92 * a `stored' block type value but not the (zero) length bytes.
94 static int zlib_inflate_packet_flush(inflate_blocks_statef
*s
)
103 int zlib_inflateInit_(
109 return zlib_inflateInit2_(z
, DEF_WBITS
, version
, stream_size
);
114 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=trv;}
115 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
125 if (z
== NULL
|| z
->state
== NULL
|| z
->next_in
== NULL
)
126 return Z_STREAM_ERROR
;
127 trv
= f
== Z_FINISH
? Z_BUF_ERROR
: Z_OK
;
129 while (1) switch (z
->state
->mode
)
133 if (((z
->state
->sub
.method
= NEXTBYTE
) & 0xf) != Z_DEFLATED
)
135 z
->state
->mode
= I_BAD
;
136 z
->msg
= (char*)"unknown compression method";
137 z
->state
->sub
.marker
= 5; /* can't try inflateSync */
140 if ((z
->state
->sub
.method
>> 4) + 8 > z
->state
->wbits
)
142 z
->state
->mode
= I_BAD
;
143 z
->msg
= (char*)"invalid window size";
144 z
->state
->sub
.marker
= 5; /* can't try inflateSync */
147 z
->state
->mode
= FLAG
;
151 if (((z
->state
->sub
.method
<< 8) + b
) % 31)
153 z
->state
->mode
= I_BAD
;
154 z
->msg
= (char*)"incorrect header check";
155 z
->state
->sub
.marker
= 5; /* can't try inflateSync */
158 if (!(b
& PRESET_DICT
))
160 z
->state
->mode
= BLOCKS
;
163 z
->state
->mode
= DICT4
;
166 z
->state
->sub
.check
.need
= (uLong
)NEXTBYTE
<< 24;
167 z
->state
->mode
= DICT3
;
170 z
->state
->sub
.check
.need
+= (uLong
)NEXTBYTE
<< 16;
171 z
->state
->mode
= DICT2
;
174 z
->state
->sub
.check
.need
+= (uLong
)NEXTBYTE
<< 8;
175 z
->state
->mode
= DICT1
;
178 z
->state
->sub
.check
.need
+= (uLong
)NEXTBYTE
;
179 z
->adler
= z
->state
->sub
.check
.need
;
180 z
->state
->mode
= DICT0
;
183 z
->state
->mode
= I_BAD
;
184 z
->msg
= (char*)"need dictionary";
185 z
->state
->sub
.marker
= 0; /* can try inflateSync */
186 return Z_STREAM_ERROR
;
188 r
= zlib_inflate_blocks(z
->state
->blocks
, z
, r
);
189 if (f
== Z_PACKET_FLUSH
&& z
->avail_in
== 0 && z
->avail_out
!= 0)
190 r
= zlib_inflate_packet_flush(z
->state
->blocks
);
191 if (r
== Z_DATA_ERROR
)
193 z
->state
->mode
= I_BAD
;
194 z
->state
->sub
.marker
= 0; /* can try inflateSync */
199 if (r
!= Z_STREAM_END
)
202 zlib_inflate_blocks_reset(z
->state
->blocks
, z
, &z
->state
->sub
.check
.was
);
203 if (z
->state
->nowrap
)
205 z
->state
->mode
= I_DONE
;
208 z
->state
->mode
= CHECK4
;
211 z
->state
->sub
.check
.need
= (uLong
)NEXTBYTE
<< 24;
212 z
->state
->mode
= CHECK3
;
215 z
->state
->sub
.check
.need
+= (uLong
)NEXTBYTE
<< 16;
216 z
->state
->mode
= CHECK2
;
219 z
->state
->sub
.check
.need
+= (uLong
)NEXTBYTE
<< 8;
220 z
->state
->mode
= CHECK1
;
223 z
->state
->sub
.check
.need
+= (uLong
)NEXTBYTE
;
225 if (z
->state
->sub
.check
.was
!= z
->state
->sub
.check
.need
)
227 z
->state
->mode
= I_BAD
;
228 z
->msg
= (char*)"incorrect data check";
229 z
->state
->sub
.marker
= 5; /* can't try inflateSync */
232 z
->state
->mode
= I_DONE
;
238 return Z_STREAM_ERROR
;
241 if (f
!= Z_PACKET_FLUSH
)
243 z
->state
->mode
= I_BAD
;
244 z
->msg
= (char *)"need more for packet flush";
245 z
->state
->sub
.marker
= 0; /* can try inflateSync */