int _zip_fseek_to_start(struct zip_file* zf)
{
int len, ret;
zf->flags &= ~ZIP_ZF_EOF;
zf->file_fpos = 0;
zf->bytes_left = zf->za->cdir->entry[zf->file_index].uncomp_size;
zf->cbytes_left = zf->za->cdir->entry[zf->file_index].comp_size;
zf->fpos = _zip_file_get_offset_safe(zf->za, zf->file_index);
len = _zip_file_fillbuf(zf->buffer, BUFSIZE, zf);
zf->zstr->zalloc = Z_NULL;
zf->zstr->zfree = Z_NULL;
zf->zstr->opaque = NULL;
zf->zstr->next_in = (Bytef *)zf->buffer;
zf->zstr->avail_in = len;
/* negative value to tell zlib that there is no header */
if ((ret=inflateInit2(zf->zstr, -MAX_WBITS)) != Z_OK) {
_zip_error_set(&zf->error, ZIP_ER_ZLIB, ret);
return -1;
}
return 0;
}
ZIP_EXTERN ssize_t
zip_fread(struct zip_file *zf, void *outbuf, size_t toread)
{
int ret;
size_t out_before, len;
int i;
if (!zf)
return -1;
if (zf->error.zip_err != 0)
return -1;
if ((zf->flags & ZIP_ZF_EOF) || (toread == 0))
return 0;
if (zf->bytes_left == 0) {
zf->flags |= ZIP_ZF_EOF;
if (zf->flags & ZIP_ZF_CRC) {
if (zf->crc != zf->crc_orig) {
_zip_error_set(&zf->error, ZIP_ER_CRC, 0);
return -1;
}
}
return 0;
}
if ((zf->flags & ZIP_ZF_DECOMP) == 0) {
ret = _zip_file_fillbuf(outbuf, toread, zf);
if (ret > 0) {
if (zf->flags & ZIP_ZF_CRC)
zf->crc = crc32(zf->crc, (Bytef *)outbuf, ret);
zf->bytes_left -= ret;
}
return ret;
}
zf->zstr->next_out = (Bytef *)outbuf;
zf->zstr->avail_out = toread;
out_before = zf->zstr->total_out;
/* endless loop until something has been accomplished */
for (;;) {
ret = inflate(zf->zstr, Z_SYNC_FLUSH);
switch (ret) {
case Z_STREAM_END:
if (zf->zstr->total_out == out_before) {
if (zf->crc != zf->crc_orig) {
_zip_error_set(&zf->error, ZIP_ER_CRC, 0);
return -1;
}
else
return 0;
}
/* fallthrough */
case Z_OK:
len = zf->zstr->total_out - out_before;
if (len >= zf->bytes_left || len >= toread) {
if (zf->flags & ZIP_ZF_CRC)
zf->crc = crc32(zf->crc, (Bytef *)outbuf, len);
zf->bytes_left -= len;
return len;
}
break;
case Z_BUF_ERROR:
if (zf->zstr->avail_in == 0) {
i = _zip_file_fillbuf(zf->buffer, BUFSIZE, zf);
if (i == 0) {
_zip_error_set(&zf->error, ZIP_ER_INCONS, 0);
return -1;
}
else if (i < 0)
return -1;
zf->zstr->next_in = (Bytef *)zf->buffer;
zf->zstr->avail_in = i;
continue;
}
/* fallthrough */
case Z_NEED_DICT:
case Z_DATA_ERROR:
case Z_STREAM_ERROR:
case Z_MEM_ERROR:
_zip_error_set(&zf->error, ZIP_ER_ZLIB, ret);
return -1;
}
}
}
ZIP_EXTERN struct zip_file *
zip_fopen_index(struct zip *za, int fileno, int flags)
{
int len, ret;
int zfflags;
struct zip_file *zf;
if ((fileno < 0) || (fileno >= za->nentry)) {
_zip_error_set(&za->error, ZIP_ER_INVAL, 0);
return NULL;
}
if ((flags & ZIP_FL_UNCHANGED) == 0
&& ZIP_ENTRY_DATA_CHANGED(za->entry+fileno)) {
_zip_error_set(&za->error, ZIP_ER_CHANGED, 0);
return NULL;
}
if (fileno >= za->cdir->nentry) {
_zip_error_set(&za->error, ZIP_ER_INVAL, 0);
return NULL;
}
zfflags = 0;
switch (za->cdir->entry[fileno].comp_method) {
case ZIP_CM_STORE:
zfflags |= ZIP_ZF_CRC;
break;
case ZIP_CM_DEFLATE:
if ((flags & ZIP_FL_COMPRESSED) == 0)
zfflags |= ZIP_ZF_CRC | ZIP_ZF_DECOMP;
break;
default:
if ((flags & ZIP_FL_COMPRESSED) == 0) {
_zip_error_set(&za->error, ZIP_ER_COMPNOTSUPP, 0);
return NULL;
}
break;
}
zf = _zip_file_new(za);
zf->flags = zfflags;
/* zf->name = za->cdir->entry[fileno].filename; */
zf->method = za->cdir->entry[fileno].comp_method;
zf->bytes_left = za->cdir->entry[fileno].uncomp_size;
zf->cbytes_left = za->cdir->entry[fileno].comp_size;
zf->crc_orig = za->cdir->entry[fileno].crc;
if ((zf->fpos=_zip_file_get_offset(za, fileno)) == 0) {
zip_fclose(zf);
return NULL;
}
if ((zf->flags & ZIP_ZF_DECOMP) == 0)
zf->bytes_left = zf->cbytes_left;
else {
if ((zf->buffer=(char *)malloc(BUFSIZE)) == NULL) {
_zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
zip_fclose(zf);
return NULL;
}
len = _zip_file_fillbuf(zf->buffer, BUFSIZE, zf);
if (len <= 0) {
_zip_error_copy(&za->error, &zf->error);
zip_fclose(zf);
return NULL;
}
if ((zf->zstr = (z_stream *)malloc(sizeof(z_stream))) == NULL) {
_zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
zip_fclose(zf);
return NULL;
}
zf->zstr->zalloc = Z_NULL;
zf->zstr->zfree = Z_NULL;
zf->zstr->opaque = NULL;
zf->zstr->next_in = (Bytef *)zf->buffer;
zf->zstr->avail_in = len;
/* negative value to tell zlib that there is no header */
if ((ret=inflateInit2(zf->zstr, -MAX_WBITS)) != Z_OK) {
_zip_error_set(&za->error, ZIP_ER_ZLIB, ret);
zip_fclose(zf);
return NULL;
}
}
return zf;
}
