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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] libxc: add LZ4 decompression support
commit 84f04d8f0dbfc24a48ee888011ca7410b7bbafc5
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Mon Oct 7 09:42:51 2013 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Oct 7 09:42:51 2013 +0200
libxc: add LZ4 decompression support
Since there's no shared or static library to link against, this simply
re-uses the hypervisor side code. However, I only audited the code
added here for possible security issues, not the referenced code in
the hypervisor tree.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Acked-by: Keir Fraser <keir@xxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
tools/libxc/Makefile | 1 +
tools/libxc/xc_dom_bzimageloader.c | 13 +++-
tools/libxc/xc_dom_decompress.h | 8 ++
tools/libxc/xc_dom_decompress_lz4.c | 136 +++++++++++++++++++++++++++++++++++
4 files changed, 157 insertions(+), 1 deletions(-)
diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index 512a994..4c64c15 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -63,6 +63,7 @@ $(patsubst %.c,%.opic,$(ELF_SRCS-y)): CFLAGS +=
-Wno-pointer-sign
GUEST_SRCS-y += xc_dom_core.c xc_dom_boot.c
GUEST_SRCS-y += xc_dom_elfloader.c
GUEST_SRCS-$(CONFIG_X86) += xc_dom_bzimageloader.c
+GUEST_SRCS-$(CONFIG_X86) += xc_dom_decompress_lz4.c
GUEST_SRCS-$(CONFIG_ARM) += xc_dom_armzimageloader.c
GUEST_SRCS-y += xc_dom_binloader.c
GUEST_SRCS-y += xc_dom_compat_linux.c
diff --git a/tools/libxc/xc_dom_bzimageloader.c
b/tools/libxc/xc_dom_bzimageloader.c
index 3870c6d..2225699 100644
--- a/tools/libxc/xc_dom_bzimageloader.c
+++ b/tools/libxc/xc_dom_bzimageloader.c
@@ -33,7 +33,7 @@
#include <inttypes.h>
#include "xg_private.h"
-#include "xc_dom.h"
+#include "xc_dom_decompress.h"
#ifndef __MINIOS__
@@ -733,6 +733,17 @@ static int xc_dom_probe_bzimage_kernel(struct xc_dom_image
*dom)
return -EINVAL;
}
}
+ else if ( check_magic(dom, "\x02\x21", 2) )
+ {
+ ret = xc_try_lz4_decode(dom, &dom->kernel_blob, &dom->kernel_size);
+ if ( ret < 0 )
+ {
+ xc_dom_panic(dom->xch, XC_INVALID_KERNEL,
+ "%s unable to LZ4 decompress kernel\n",
+ __FUNCTION__);
+ return -EINVAL;
+ }
+ }
else
{
xc_dom_panic(dom->xch, XC_INVALID_KERNEL,
diff --git a/tools/libxc/xc_dom_decompress.h b/tools/libxc/xc_dom_decompress.h
new file mode 100644
index 0000000..42cefa3
--- /dev/null
+++ b/tools/libxc/xc_dom_decompress.h
@@ -0,0 +1,8 @@
+#ifndef __MINIOS__
+# include "xc_dom.h"
+#else
+# include "xc_dom_decompress_unsafe.h"
+#endif
+
+int xc_try_lz4_decode(struct xc_dom_image *dom, void **blob, size_t *size);
+
diff --git a/tools/libxc/xc_dom_decompress_lz4.c
b/tools/libxc/xc_dom_decompress_lz4.c
new file mode 100644
index 0000000..4787535
--- /dev/null
+++ b/tools/libxc/xc_dom_decompress_lz4.c
@@ -0,0 +1,136 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <endian.h>
+#include <stdint.h>
+
+#include "xg_private.h"
+#include "xc_dom_decompress.h"
+
+#define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+#define likely(a) a
+#define unlikely(a) a
+
+static inline uint_fast16_t le16_to_cpup(const unsigned char *buf)
+{
+ return buf[0] | (buf[1] << 8);
+}
+
+static inline uint_fast32_t le32_to_cpup(const unsigned char *buf)
+{
+ return le16_to_cpup(buf) | ((uint32_t)le16_to_cpup(buf + 2) << 16);
+}
+
+#include "../../xen/include/xen/lz4.h"
+#include "../../xen/common/decompress.h"
+
+#ifndef __MINIOS__
+
+#include "../../xen/common/lz4/decompress.c"
+
+#define ARCHIVE_MAGICNUMBER 0x184C2102
+
+int xc_try_lz4_decode(
+ struct xc_dom_image *dom, void **blob, size_t *psize)
+{
+ int ret = -1;
+ unsigned char *inp = *blob, *output, *outp;
+ ssize_t size = *psize - 4;
+ size_t out_len, dest_len, chunksize;
+ const char *msg;
+
+ if (size < 4) {
+ msg = "input too small";
+ goto exit_0;
+ }
+
+ out_len = get_unaligned_le32(inp + size);
+ if (xc_dom_kernel_check_size(dom, out_len)) {
+ msg = "Decompressed image too large";
+ goto exit_0;
+ }
+
+ output = malloc(out_len);
+ if (!output) {
+ msg = "Could not allocate output buffer";
+ goto exit_0;
+ }
+ outp = output;
+
+ chunksize = get_unaligned_le32(inp);
+ if (chunksize == ARCHIVE_MAGICNUMBER) {
+ inp += 4;
+ size -= 4;
+ } else {
+ msg = "invalid header";
+ goto exit_2;
+ }
+
+ for (;;) {
+ if (size < 4) {
+ msg = "missing data";
+ goto exit_2;
+ }
+ chunksize = get_unaligned_le32(inp);
+ if (chunksize == ARCHIVE_MAGICNUMBER) {
+ inp += 4;
+ size -= 4;
+ continue;
+ }
+ inp += 4;
+ size -= 4;
+ if (chunksize > size) {
+ msg = "insufficient input data";
+ goto exit_2;
+ }
+
+ dest_len = out_len - (outp - output);
+ ret = lz4_decompress_unknownoutputsize(inp, chunksize, outp,
+ &dest_len);
+ if (ret < 0) {
+ msg = "decoding failed";
+ goto exit_2;
+ }
+
+ outp += dest_len;
+ size -= chunksize;
+
+ if (size == 0)
+ {
+ *blob = output;
+ *psize = out_len;
+ return 0;
+ }
+
+ if (size < 0) {
+ msg = "data corrupted";
+ goto exit_2;
+ }
+
+ inp += chunksize;
+ }
+
+exit_2:
+ free(output);
+exit_0:
+ DOMPRINTF("LZ4 decompression error: %s\n", msg);
+ return ret;
+}
+
+#else /* __MINIOS__ */
+
+#include "../../xen/common/unlz4.c"
+
+int xc_try_lz4_decode(
+ struct xc_dom_image *dom, void **blob, size_t *size)
+{
+ return xc_dom_decompress_unsafe(unlz4, dom, blob, size);
+}
+
+#endif
--
generated by git-patchbot for /home/xen/git/xen.git#master
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