1*74a4d8c2SCharles.Forsyth #include "lib9.h"
2*74a4d8c2SCharles.Forsyth #include <flate.h>
3*74a4d8c2SCharles.Forsyth #include "zlib.h"
4*74a4d8c2SCharles.Forsyth
5*74a4d8c2SCharles.Forsyth typedef struct Block Block;
6*74a4d8c2SCharles.Forsyth
7*74a4d8c2SCharles.Forsyth struct Block
8*74a4d8c2SCharles.Forsyth {
9*74a4d8c2SCharles.Forsyth uchar *pos;
10*74a4d8c2SCharles.Forsyth uchar *limit;
11*74a4d8c2SCharles.Forsyth };
12*74a4d8c2SCharles.Forsyth
13*74a4d8c2SCharles.Forsyth static int
blgetc(void * vb)14*74a4d8c2SCharles.Forsyth blgetc(void *vb)
15*74a4d8c2SCharles.Forsyth {
16*74a4d8c2SCharles.Forsyth Block *b;
17*74a4d8c2SCharles.Forsyth
18*74a4d8c2SCharles.Forsyth b = vb;
19*74a4d8c2SCharles.Forsyth if(b->pos >= b->limit)
20*74a4d8c2SCharles.Forsyth return -1;
21*74a4d8c2SCharles.Forsyth return *b->pos++;
22*74a4d8c2SCharles.Forsyth }
23*74a4d8c2SCharles.Forsyth
24*74a4d8c2SCharles.Forsyth static int
blwrite(void * vb,void * buf,int n)25*74a4d8c2SCharles.Forsyth blwrite(void *vb, void *buf, int n)
26*74a4d8c2SCharles.Forsyth {
27*74a4d8c2SCharles.Forsyth Block *b;
28*74a4d8c2SCharles.Forsyth
29*74a4d8c2SCharles.Forsyth b = vb;
30*74a4d8c2SCharles.Forsyth
31*74a4d8c2SCharles.Forsyth if(n > b->limit - b->pos)
32*74a4d8c2SCharles.Forsyth n = b->limit - b->pos;
33*74a4d8c2SCharles.Forsyth memmove(b->pos, buf, n);
34*74a4d8c2SCharles.Forsyth b->pos += n;
35*74a4d8c2SCharles.Forsyth return n;
36*74a4d8c2SCharles.Forsyth }
37*74a4d8c2SCharles.Forsyth
38*74a4d8c2SCharles.Forsyth int
inflatezlibblock(uchar * dst,int dsize,uchar * src,int ssize)39*74a4d8c2SCharles.Forsyth inflatezlibblock(uchar *dst, int dsize, uchar *src, int ssize)
40*74a4d8c2SCharles.Forsyth {
41*74a4d8c2SCharles.Forsyth Block bd, bs;
42*74a4d8c2SCharles.Forsyth int ok;
43*74a4d8c2SCharles.Forsyth
44*74a4d8c2SCharles.Forsyth if(ssize < 6)
45*74a4d8c2SCharles.Forsyth return FlateInputFail;
46*74a4d8c2SCharles.Forsyth
47*74a4d8c2SCharles.Forsyth if(((src[0] << 8) | src[1]) % 31)
48*74a4d8c2SCharles.Forsyth return FlateCorrupted;
49*74a4d8c2SCharles.Forsyth if((src[0] & ZlibMeth) != ZlibDeflate
50*74a4d8c2SCharles.Forsyth || (src[0] & ZlibCInfo) > ZlibWin32k)
51*74a4d8c2SCharles.Forsyth return FlateCorrupted;
52*74a4d8c2SCharles.Forsyth
53*74a4d8c2SCharles.Forsyth bs.pos = src + 2;
54*74a4d8c2SCharles.Forsyth bs.limit = src + ssize - 6;
55*74a4d8c2SCharles.Forsyth
56*74a4d8c2SCharles.Forsyth bd.pos = dst;
57*74a4d8c2SCharles.Forsyth bd.limit = dst + dsize;
58*74a4d8c2SCharles.Forsyth
59*74a4d8c2SCharles.Forsyth ok = inflate(&bd, blwrite, &bs, blgetc);
60*74a4d8c2SCharles.Forsyth if(ok != FlateOk)
61*74a4d8c2SCharles.Forsyth return ok;
62*74a4d8c2SCharles.Forsyth
63*74a4d8c2SCharles.Forsyth if(adler32(1, dst, bs.pos - dst) != ((bs.pos[0] << 24) | (bs.pos[1] << 16) | (bs.pos[2] << 8) | bs.pos[3]))
64*74a4d8c2SCharles.Forsyth return FlateCorrupted;
65*74a4d8c2SCharles.Forsyth
66*74a4d8c2SCharles.Forsyth return bd.pos - dst;
67*74a4d8c2SCharles.Forsyth }
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