[Libguestfs] [PATCH v4 1/5] add HIVEX_OPEN_UNSAFE flag.

[Dawid Zamirski]

This flag will be used to control behavior of libhivex API functions so
that they tolerate corruption in hives by either using heuristic
recovery from unexpected situations or simply ignore bad registry
keys/values whenever possible.
---
 generator/generator.ml | 8 ++++++++
 lib/handle.c           | 1 +
 lib/hivex-internal.h   | 1 +
 3 files changed, 10 insertions(+)

diff --git a/generator/generator.ml b/generator/generator.ml
index e71a0e7..4125ae7 100755
--- a/generator/generator.ml
+++ b/generator/generator.ml
@@ -113,6 +113,7 @@ let open_flags = [
   1, "VERBOSE", "Verbose messages";
   2, "DEBUG", "Debug messages";
   4, "WRITE", "Enable writes to the hive";
+  8, "UNSAFE", "Enable heuristics to allow read/write of corrupted hives";
 ]
 
 (* The API calls. *)
@@ -145,6 +146,13 @@ Open the hive for writing.  If omitted, the hive is read-only.
 
 See L<hivex(3)/WRITING TO HIVE FILES>.
 
+=item HIVEX_OPEN_UNSAFE
+
+Open the hive in unsafe mode that enables heuristics to handle corrupted hives.
+
+This may allow to read or write registry keys/values that appear intact in an
+otherwise corrupted hive. Use at your own risk.
+
 =back";
 
   "close", (RErrDispose, [AHive]),
diff --git a/lib/handle.c b/lib/handle.c
index d33c1d0..a4982dd 100644
--- a/lib/handle.c
+++ b/lib/handle.c
@@ -83,6 +83,7 @@ hivex_open (const char *filename, int flags)
   DEBUG (2, "created handle %p", h);
 
   h->writable = !!(flags & HIVEX_OPEN_WRITE);
+  h->unsafe = !!(flags & HIVEX_OPEN_UNSAFE);
   h->filename = strdup (filename);
   if (h->filename == NULL)
     goto error;
diff --git a/lib/hivex-internal.h b/lib/hivex-internal.h
index 26f4964..9a497ed 100644
--- a/lib/hivex-internal.h
+++ b/lib/hivex-internal.h
@@ -41,6 +41,7 @@ struct hive_h {
   size_t size;
   int msglvl;                   /* 1 = verbose, 2 or 3 = debug */
   int writable;
+  int unsafe;
 
   /* Registry file, memory mapped if read-only, or malloc'd if writing. */
   union {
-- 
2.9.3