Loader: ELF non-zero based PIC binaries support

cle/address_translator.py

@@ -0,0 +1,95 @@
+class AddressTranslator(object):
+    """
+    Mediates address translations between typed addresses such as RAW, RVA, LVA, MVA and VA
+    including address owner and its state (linked or mapped)
+
+    Semantics:
+        owner - object associated with the address
+            (any object class based on `cle.Backend`)
+        owner mapping state - sparse object can be either mapped or not
+            (actual object's image base VA to be considered valid)
+        RAW - offset (index) inside a file stream
+        VA  - address inside process flat virtual memory space
+        RVA - address relative to the object's segment base
+            (segment base normalized virtual address)
+        LVA - linked VA (linker)
+        MVA - mapped VA (loader)
+    """
+
+    def __init__(self, rva, owner):
+        """
+        :param rva: virtual address relative to owner's object image base
+        :type rva: int
+        :param owner: The object owner address relates to
+        :type owner: cle.Backend
+        """
+        self._rva, self._owner = rva, owner
+
+    @classmethod
+    def from_lva(cls, lva, owner):
+        """
+        Loads address translator with LVA
+        """
+        return cls(lva - owner.linked_base, owner)
+
+    @classmethod
+    def from_mva(cls, mva, owner):
+        """
+        Loads address translator with MVA
+        """
+        return cls(mva - owner.mapped_base, owner)
+
+    @classmethod
+    def from_rva(cls, rva, owner):
+        """
+        Loads address translator with RVA
+        """
+        return cls(rva, owner)
+
+    @classmethod
+    def from_raw(cls, raw, owner):
+        """
+        Loads address translator with RAW address
+        """
+        return cls(owner.offset_to_addr(raw) - (owner.mapped_base if owner._is_mapped else owner.linked_base), owner)
+
+    from_linked_va = from_lva
+    from_va = from_mapped_va = from_mva
+    from_relative_va = from_rva
+
+    def to_lva(self):
+        """
+        VA -> LVA
+        :rtype: int
+        """
+        return self._rva + self._owner.linked_base
+
+    def to_mva(self):
+        """
+        RVA -> MVA
+        :rtype: int
+        """
+        return self._rva + self._owner.mapped_base
+
+    def to_rva(self):
+        """
+        RVA -> RVA
+        :rtype: int
+        """
+        return self._rva
+
+    def to_raw(self):
+        """
+        RVA -> RAW
+        :rtype: int
+        """
+        return self._owner.addr_to_offset(
+            self._rva + (self._owner.mapped_base if self._owner._is_mapped else self._owner.linked_base)
+        )
+
+    to_linked_va = to_lva
+    to_va = to_mapped_va = to_mva
+    to_relative_va = to_rva
+
+
+AT = AddressTranslator