Subversion Repositories planix.SVN

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
#include <u.h>
2 
#include <libc.h>
3 
#include <flate.h>
4 
#include "zlib.h"
5 
 
6 
typedef struct Block	Block;
7 
 
8 
struct Block
9 
{
10 
	uchar	*pos;
11 
	uchar	*limit;
12 
};
13 
 
14 
static int
15 
blgetc(void *vb)
16 
{
17 
	Block *b;
18 
 
19 
	b = vb;
20 
	if(b->pos >= b->limit)
21 
		return -1;
22 
	return *b->pos++;
23 
}
24 
 
25 
static int
26 
blwrite(void *vb, void *buf, int n)
27 
{
28 
	Block *b;
29 
 
30 
	b = vb;
31 
 
32 
	if(n > b->limit - b->pos)
33 
		n = b->limit - b->pos;
34 
	memmove(b->pos, buf, n);
35 
	b->pos += n;
36 
	return n;
37 
}
38 
 
39 
int
40 
inflatezlibblock(uchar *dst, int dsize, uchar *src, int ssize)
41 
{
42 
	Block bd, bs;
43 
	int ok;
44 
 
45 
	if(ssize < 6)
46 
		return FlateInputFail;
47 
 
48 
	if(((src[0] << 8) | src[1]) % 31)
49 
		return FlateCorrupted;
50 
	if((src[0] & ZlibMeth) != ZlibDeflate
51 
	|| (src[0] & ZlibCInfo) > ZlibWin32k)
52 
		return FlateCorrupted;
53 
 
54 
	bs.pos = src + 2;
55 
	bs.limit = src + ssize - 6;
56 
 
57 
	bd.pos = dst;
58 
	bd.limit = dst + dsize;
59 
 
60 
	ok = inflate(&bd, blwrite, &bs, blgetc);
61 
	if(ok != FlateOk)
62 
		return ok;
63 
 
64 
	if(adler32(1, dst, bs.pos - dst) != ((bs.pos[0] << 24) | (bs.pos[1] << 16) | (bs.pos[2] << 8) | bs.pos[3]))
65 
		return FlateCorrupted;
66 
 
67 
	return bd.pos - dst;
68 
}