freebsd-skq/sys/geom/uzip/g_uzip_lzma.c
sobomax fa8fbeaaf4 1.Improve handling around last compressed block of the file, which is
necessary because CLOOP format lacks explicit EOF or length, so that
  in the presence of padding or when the CLOOP is put onto a larger
  partition upper level provider size may be larger. Bound amount
  of extra data that we might touch to the max length of the compressed
  block and detect zero-padding in the last cluster, which when
  sector is all-zero might cause us to emit bogus I/O error after
  decompression of that fails. To not make code any more complicated
  that it needs to be deal with it in lazy-manner, i.e. when we
  first access that specific cluster.

  This change also fixes stupid mistake in the LZMA code, inherited
  from geom_lzma, which does not share length of the output buffer
  buffer with the decompression routine, so that in the presence
  of corrupted or purposedly tailored data may easily cause heap
  overflow and kernel memory corruption.

  Beef up validation of the CLOOP TOC by checking that lengths of
  all but the last compressed clusters match upper limit set by
  the decompressor and improve some error diagnostic output while
  I am here.

2.Add kern.geom.uzip.attach_to tunable to artifically limit
  attaching uzip to certain devices in the dev tree only.

    For example the following only makes us attaching to the
    GPT labels:

    kern.geom.uzip.attach_to="gpt/*"

3.Add kern.geom.uzip.noattach_to, which does opposite to the (2)
  above, i.e. prevents geom_uzip from tasting / attaching to
  providers matching some pattern. By default we don't attach
  to our own kind, i.e. kern.geom.uzip.noattach_to="*.uzip".
  It saves us quite some CPU cycles, esp on low-end embedded
  systems.

Approved by:	re (gjb)
Differential Revision:	https://reviews.freebsd.org/D7013
2016-06-29 18:19:05 +00:00

129 lines
3.5 KiB
C

/*-
* Copyright (c) 2004 Max Khon
* Copyright (c) 2014 Juniper Networks, Inc.
* Copyright (c) 2006-2016 Maxim Sobolev <sobomax@FreeBSD.org>
* Copyright (c) 2010-2012 Aleksandr Rybalko
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <contrib/xz-embedded/linux/include/linux/xz.h>
#include <geom/uzip/g_uzip.h>
#include <geom/uzip/g_uzip_dapi.h>
#include <geom/uzip/g_uzip_lzma.h>
struct g_uzip_lzma {
struct g_uzip_dapi pub;
uint32_t blksz;
/* XZ decoder structs */
struct xz_buf b;
struct xz_dec *s;
};
static int g_uzip_lzma_nop(struct g_uzip_dapi *, const char *);
static void
g_uzip_lzma_free(struct g_uzip_dapi *lzpp)
{
struct g_uzip_lzma *lzp;
lzp = (struct g_uzip_lzma *)lzpp->pvt;
if (lzp->s != NULL) {
xz_dec_end(lzp->s);
lzp->s = NULL;
}
free(lzp, M_GEOM_UZIP);
}
static int
g_uzip_lzma_decompress(struct g_uzip_dapi *lzpp, const char *gp_name,
void *ibp, size_t ilen, void *obp)
{
struct g_uzip_lzma *lzp;
int err;
lzp = (struct g_uzip_lzma *)lzpp->pvt;
lzp->b.in = ibp;
lzp->b.out = obp;
lzp->b.in_pos = lzp->b.out_pos = 0;
lzp->b.in_size = ilen;
lzp->b.out_size = lzp->blksz;
err = (xz_dec_run(lzp->s, &lzp->b) != XZ_STREAM_END) ? 1 : 0;
/* TODO decoder recovery, if needed */
if (err != 0) {
printf("%s: ibp=%p, obp=%p, in_pos=%jd, out_pos=%jd, "
"in_size=%jd, out_size=%jd\n", __func__, ibp, obp,
(intmax_t)lzp->b.in_pos, (intmax_t)lzp->b.out_pos,
(intmax_t)lzp->b.in_size, (intmax_t)lzp->b.out_size);
}
return (err);
}
static int
LZ4_compressBound(int isize)
{
return (isize + (isize / 255) + 16);
}
struct g_uzip_dapi *
g_uzip_lzma_ctor(uint32_t blksz)
{
struct g_uzip_lzma *lzp;
lzp = malloc(sizeof(struct g_uzip_lzma), M_GEOM_UZIP, M_WAITOK);
xz_crc32_init();
lzp->s = xz_dec_init(XZ_SINGLE, 0);
if (lzp->s == NULL) {
goto e1;
}
lzp->blksz = blksz;
lzp->pub.max_blen = LZ4_compressBound(blksz);
lzp->pub.decompress = &g_uzip_lzma_decompress;
lzp->pub.free = &g_uzip_lzma_free;
lzp->pub.rewind = &g_uzip_lzma_nop;
lzp->pub.pvt = lzp;
return (&lzp->pub);
e1:
free(lzp, M_GEOM_UZIP);
return (NULL);
}
static int
g_uzip_lzma_nop(struct g_uzip_dapi *zpp, const char *gp_name)
{
return (0);
}