Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <flate.h>
#include "zlib.h"

typedef struct ZWrite   ZWrite;

struct ZWrite
{
        ulong   adler;
        void    *wr;
        int     (*w)(void*, void*, int);
};

static int
zlwrite(void *vzw, void *buf, int n)
{
        ZWrite *zw;

        zw = vzw;
        zw->adler = adler32(zw->adler, buf, n);
        n = (*zw->w)(zw->wr, buf, n);
        if(n <= 0)
                return n;
        return n;
}

int
inflatezlib(void *wr, int (*w)(void*, void*, int), void *getr, int (*get)(void*))
{
        ZWrite zw;
        ulong v;
        int c, i;

        c = (*get)(getr);
        if(c < 0)
                return FlateInputFail;
        i = (*get)(getr);
        if(i < 0)
                return FlateInputFail;

        if(((c << 8) | i) % 31)
                return FlateCorrupted;
        if((c & ZlibMeth) != ZlibDeflate
        || (c & ZlibCInfo) > ZlibWin32k)
                return FlateCorrupted;

        zw.wr = wr;
        zw.w = w;
        zw.adler = 1;
        i = inflate(&zw, zlwrite, getr, get);
        if(i != FlateOk)
                return i;

        v = 0;
        for(i = 0; i < 4; i++){
                c = (*get)(getr);
                if(c < 0)
                        return FlateInputFail;
                v = (v << 8) | c;
        }
        if(zw.adler != v)
                return FlateCorrupted;

        return FlateOk;
}