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@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/tools/libxc/xc_dom_bzimageloader.c b/tools/libxc/xc_dom_bzimageloader.c
index 3870c6d5f5..2225699b8a 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,