int xc_dom_try_gunzip(struct xc_dom_image *dom, void **blob, size_t * size)
{
void *unzip;
size_t unziplen;
unziplen = xc_dom_check_gzip(dom->xch, *blob, *size);
if ( unziplen == 0 )
return 0;
if ( xc_dom_kernel_check_size(dom, unziplen) )
return 0;
unzip = xc_dom_malloc(dom, unziplen);
if ( unzip == NULL )
return -1;
if ( xc_dom_do_gunzip(dom->xch, *blob, *size, unzip, unziplen) == -1 )
return -1;
*blob = unzip;
*size = unziplen;
return 0;
}
static int xc_try_lzo1x_decode(
struct xc_dom_image *dom, void **blob, size_t *size)
{
int ret;
const unsigned char *cur = dom->kernel_blob;
unsigned char *out_buf = NULL;
size_t left = dom->kernel_size;
const char *msg;
unsigned version;
static const unsigned char magic[] = {
0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a
};
/*
* lzo_uint should match size_t. Check that this is the case to be
* sure we won't overflow various lzo_uint fields.
*/
BUILD_BUG_ON(sizeof(lzo_uint) != sizeof(size_t));
ret = lzo_init();
if ( ret != LZO_E_OK )
{
DOMPRINTF("LZO1x: Failed to init library (%d)\n", ret);
return -1;
}
if ( left < 16 || memcmp(cur, magic, 9) )
{
DOMPRINTF("LZO1x: Unrecognized magic\n");
return -1;
}
/* get version (2bytes), skip library version (2),
* 'need to be extracted' version (2) and method (1) */
version = lzo_read_16(cur + 9);
cur += 16;
left -= 16;
if ( version >= 0x0940 )
{
/* skip level */
++cur;
if ( left )
--left;
}
if ( left >= 4 && (lzo_read_32(cur) & LZOP_HEADER_HAS_FILTER) )
ret = 8; /* flags + filter info */
else
ret = 4; /* flags */
/* skip mode and mtime_low */
ret += 8;
if ( version >= 0x0940 )
ret += 4; /* skip mtime_high */
/* don't care about the file name, and skip checksum */
if ( left > ret )
ret += 1 + cur[ret] + 4;
if ( left < ret )
{
DOMPRINTF("LZO1x: Incomplete header\n");
return -1;
}
cur += ret;
left -= ret;
for ( *size = 0; ; )
{
lzo_uint src_len, dst_len, out_len;
unsigned char *tmp_buf;
msg = "Short input";
if ( left < 4 )
break;
dst_len = lzo_read_32(cur);
if ( !dst_len )
{
msg = "Error registering stream output";
if ( xc_dom_register_external(dom, out_buf, *size) )
break;
return 0;
}
if ( dst_len > LZOP_MAX_BLOCK_SIZE )
{
msg = "Block size too large";
break;
}
if ( left < 12 )
break;
src_len = lzo_read_32(cur + 4);
cur += 12; /* also skip block checksum info */
left -= 12;
msg = "Bad source length";
if ( src_len <= 0 || src_len > dst_len || src_len > left )
break;
msg = "Output buffer overflow";
if ( *size > SIZE_MAX - dst_len )
break;
msg = "Decompressed image too large";
if ( xc_dom_kernel_check_size(dom, *size + dst_len) )
break;
msg = "Failed to (re)alloc memory";
tmp_buf = realloc(out_buf, *size + dst_len);
if ( tmp_buf == NULL )
break;
out_buf = tmp_buf;
out_len = dst_len;
ret = lzo1x_decompress_safe(cur, src_len,
out_buf + *size, &out_len, NULL);
switch ( ret )
{
case LZO_E_OK:
msg = "Input underrun";
if ( out_len != dst_len )
break;
*blob = out_buf;
*size += out_len;
cur += src_len;
left -= src_len;
continue;
case LZO_E_INPUT_NOT_CONSUMED:
msg = "Unconsumed input";
break;
case LZO_E_OUTPUT_OVERRUN:
msg = "Output overrun";
break;
case LZO_E_INPUT_OVERRUN:
msg = "Input overrun";
break;
case LZO_E_LOOKBEHIND_OVERRUN:
msg = "Look-behind overrun";
break;
case LZO_E_EOF_NOT_FOUND:
msg = "No EOF marker";
break;
case LZO_E_ERROR:
msg = "General error";
break;
default:
msg = "Internal program error (bug)";
break;
}
break;
}
free(out_buf);
DOMPRINTF("LZO1x decompression error: %s\n", msg);
return -1;
}
static int xc_try_bzip2_decode(
struct xc_dom_image *dom, void **blob, size_t *size)
{
bz_stream stream;
int ret;
char *out_buf;
char *tmp_buf;
int retval = -1;
unsigned int outsize;
uint64_t total;
stream.bzalloc = NULL;
stream.bzfree = NULL;
stream.opaque = NULL;
if ( dom->kernel_size == 0)
{
DOMPRINTF("BZIP2: Input is 0 size");
return -1;
}
ret = BZ2_bzDecompressInit(&stream, 0, 0);
if ( ret != BZ_OK )
{
DOMPRINTF("BZIP2: Error initting stream");
return -1;
}
/* sigh. We don't know up-front how much memory we are going to need
* for the output buffer. Allocate the output buffer to be equal
* the input buffer to start, and we'll realloc as needed.
*/
outsize = dom->kernel_size;
/*
* stream.avail_in and outsize are unsigned int, while kernel_size
* is a size_t. Check we aren't overflowing.
*/
if ( outsize != dom->kernel_size )
{
DOMPRINTF("BZIP2: Input too large");
goto bzip2_cleanup;
}
out_buf = malloc(outsize);
if ( out_buf == NULL )
{
DOMPRINTF("BZIP2: Failed to alloc memory");
goto bzip2_cleanup;
}
stream.next_in = dom->kernel_blob;
stream.avail_in = dom->kernel_size;
stream.next_out = out_buf;
stream.avail_out = dom->kernel_size;
for ( ; ; )
{
ret = BZ2_bzDecompress(&stream);
if ( ret == BZ_STREAM_END )
{
DOMPRINTF("BZIP2: Saw data stream end");
retval = 0;
break;
}
if ( ret != BZ_OK )
{
DOMPRINTF("BZIP2: error %d", ret);
free(out_buf);
goto bzip2_cleanup;
}
if ( stream.avail_out == 0 )
{
/* Protect against output buffer overflow */
if ( outsize > UINT_MAX / 2 )
{
DOMPRINTF("BZIP2: output buffer overflow");
free(out_buf);
goto bzip2_cleanup;
}
if ( xc_dom_kernel_check_size(dom, outsize * 2) )
{
DOMPRINTF("BZIP2: output too large");
free(out_buf);
goto bzip2_cleanup;
}
tmp_buf = realloc(out_buf, outsize * 2);
if ( tmp_buf == NULL )
{
DOMPRINTF("BZIP2: Failed to realloc memory");
free(out_buf);
goto bzip2_cleanup;
}
out_buf = tmp_buf;
stream.next_out = out_buf + outsize;
stream.avail_out = (outsize * 2) - outsize;
outsize *= 2;
}
else if ( stream.avail_in == 0 )
{
/*
* If there is output buffer available then this indicates
* that BZ2_bzDecompress would like more input data to be
* provided. However our complete input buffer is in
* memory and provided upfront so if avail_in is zero this
* actually indicates a truncated input.
*/
DOMPRINTF("BZIP2: not enough input");
free(out_buf);
goto bzip2_cleanup;
}
}
total = (((uint64_t)stream.total_out_hi32) << 32) | stream.total_out_lo32;
if ( xc_dom_register_external(dom, out_buf, total) )
{
DOMPRINTF("BZIP2: Error registering stream output");
free(out_buf);
goto bzip2_cleanup;
}
DOMPRINTF("%s: BZIP2 decompress OK, 0x%zx -> 0x%lx",
__FUNCTION__, *size, (long unsigned int) total);
*blob = out_buf;
*size = total;
bzip2_cleanup:
BZ2_bzDecompressEnd(&stream);
return retval;
}
static int _xc_try_lzma_decode(
struct xc_dom_image *dom, void **blob, size_t *size,
lzma_stream *stream, const char *what)
{
lzma_ret ret;
lzma_action action = LZMA_RUN;
unsigned char *out_buf;
unsigned char *tmp_buf;
int retval = -1;
size_t outsize;
const char *msg;
if ( dom->kernel_size == 0)
{
DOMPRINTF("%s: Input is 0 size", what);
return -1;
}
/* sigh. We don't know up-front how much memory we are going to need
* for the output buffer. Allocate the output buffer to be equal
* the input buffer to start, and we'll realloc as needed.
*/
outsize = dom->kernel_size;
out_buf = malloc(outsize);
if ( out_buf == NULL )
{
DOMPRINTF("%s: Failed to alloc memory", what);
goto lzma_cleanup;
}
stream->next_in = dom->kernel_blob;
stream->avail_in = dom->kernel_size;
stream->next_out = out_buf;
stream->avail_out = dom->kernel_size;
for ( ; ; )
{
ret = lzma_code(stream, action);
if ( ret == LZMA_STREAM_END )
{
DOMPRINTF("%s: Saw data stream end", what);
retval = 0;
break;
}
if ( ret != LZMA_OK )
{
switch ( ret )
{
case LZMA_MEM_ERROR:
msg = strerror(ENOMEM);
break;
case LZMA_MEMLIMIT_ERROR:
msg = "Memory usage limit reached";
break;
case LZMA_FORMAT_ERROR:
msg = "File format not recognized";
break;
case LZMA_OPTIONS_ERROR:
// FIXME: Better message?
msg = "Unsupported compression options";
break;
case LZMA_DATA_ERROR:
msg = "File is corrupt";
break;
case LZMA_BUF_ERROR:
msg = "Unexpected end of input";
break;
default:
msg = "Internal program error (bug)";
break;
}
DOMPRINTF("%s: %s decompression error: %s",
__FUNCTION__, what, msg);
free(out_buf);
goto lzma_cleanup;
}
if ( stream->avail_out == 0 )
{
/* Protect against output buffer overflow */
if ( outsize > SIZE_MAX / 2 )
{
DOMPRINTF("%s: output buffer overflow", what);
free(out_buf);
goto lzma_cleanup;
}
if ( xc_dom_kernel_check_size(dom, outsize * 2) )
{
DOMPRINTF("%s: output too large", what);
free(out_buf);
goto lzma_cleanup;
}
tmp_buf = realloc(out_buf, outsize * 2);
if ( tmp_buf == NULL )
{
DOMPRINTF("%s: Failed to realloc memory", what);
free(out_buf);
goto lzma_cleanup;
}
out_buf = tmp_buf;
stream->next_out = out_buf + outsize;
stream->avail_out = (outsize * 2) - outsize;
outsize *= 2;
}
}
if ( xc_dom_register_external(dom, out_buf, stream->total_out) )
{
DOMPRINTF("%s: Error registering stream output", what);
free(out_buf);
goto lzma_cleanup;
}
DOMPRINTF("%s: %s decompress OK, 0x%zx -> 0x%zx",
__FUNCTION__, what, *size, (size_t)stream->total_out);
*blob = out_buf;
*size = stream->total_out;
lzma_cleanup:
lzma_end(stream);
return retval;
}
