[HB] Add Sanitizer

This commit is contained in:
Behdad Esfahbod 2009-08-04 20:52:47 -04:00
parent 2765d333e5
commit 4e8a0602bb
1 changed files with 53 additions and 5 deletions

View File

@ -212,8 +212,8 @@ struct _hb_sanitize_context_t
};
static HB_GNUC_UNUSED void
hb_sanitize_init (hb_sanitize_context_t *context,
hb_blob_t *blob)
_hb_sanitize_init (hb_sanitize_context_t *context,
hb_blob_t *blob)
{
context->blob = blob;
context->start = hb_blob_lock (blob);
@ -222,14 +222,15 @@ hb_sanitize_init (hb_sanitize_context_t *context,
}
static HB_GNUC_UNUSED void
hb_sanitize_fini (hb_sanitize_context_t *context, bool unlock)
_hb_sanitize_fini (hb_sanitize_context_t *context,
bool unlock)
{
if (unlock)
hb_blob_unlock (context->blob);
}
static HB_GNUC_UNUSED bool
hb_sanitize_edit (hb_sanitize_context_t *context)
_hb_sanitize_edit (hb_sanitize_context_t *context)
{
bool perm = hb_blob_try_writeable_inplace (context->blob);
if (perm)
@ -258,9 +259,56 @@ hb_sanitize_edit (hb_sanitize_context_t *context)
#define SANITIZE_MEM(B,L) HB_LIKELY (context->start <= CONST_CHARP(B) && CONST_CHARP(B) + (L) <= context->end) /* XXX overflow */
#define NEUTER(Var, Val) (SANITIZE_OBJ (Var) && hb_sanitize_edit (context) && ((Var) = (Val), true))
#define NEUTER(Var, Val) (SANITIZE_OBJ (Var) && _hb_sanitize_edit (context) && ((Var) = (Val), true))
/* Template to sanitize an object. */
template <typename Type>
struct Sanitizer
{
static hb_blob_t *sanitize (hb_blob_t *blob) {
hb_sanitize_context_t context;
bool sane;
/* XXX is_sane() stuff */
retry:
_hb_sanitize_init (&context, blob);
Type *t = &CAST (Type, context.start, 0);
sane = t->sanitize (&context);
if (sane) {
if (context.edit_count) {
/* sanitize again to ensure not toe-stepping */
context.edit_count = 0;
sane = t->sanitize (&context);
if (context.edit_count) {
sane = false;
}
}
_hb_sanitize_fini (&context, true);
} else {
_hb_sanitize_fini (&context, true);
if (context.edit_count && !hb_blob_is_writeable (blob) && hb_blob_try_writeable (blob)) {
/* ok, we made it writeable by relocating. try again */
goto retry;
}
}
if (sane)
return blob;
else {
hb_blob_destroy (blob);
return hb_blob_create_empty ();
}
}
static const Type& instantiate (hb_blob_t *blob) {
return Type::get_for_data (hb_blob_lock (blob));
}
};
/*
*