Add in initial version of breakpointing

volatility3/cli/volshell/generic.py

@@ -3,6 +3,7 @@
 #
 import binascii
 import code
+import functools
 import io
 import random
 import string
@@ -187,6 +188,7 @@ class Volshell(interfaces.plugins.PluginInterface):
     def construct_locals(self) -> List[Tuple[List[str], Any]]:
         """Returns a listing of the functions to be added to the environment."""
         return [
+            (["bp", "breakpoint"], self.breakpoint),
             (["dt", "display_type"], self.display_type),
             (["db", "display_bytes"], self.display_bytes),
             (["dw", "display_words"], self.display_words),
@@ -797,6 +799,36 @@ class Volshell(interfaces.plugins.PluginInterface):
 
         return constructed
 
+    def breakpoint(self, address: int, layer_name: Optional[str] = None) -> None:
+        """Sets a breakpoint on a particular address (within a specific layer)"""
+        if layer_name is None:
+            if self.current_layer is None:
+                raise ValueError("Current layer must be set")
+            layer_name = self.current_layer
+
+        layer: interfaces.layers.DataLayerInterface = self.context.layers[layer_name]
+        # Check if the read value is already overloaded
+        if not hasattr(layer.read, "breakpoints"):
+            # Layer read is not yet wrapped
+            def wrapped_read(offset: int, length: int, pad: bool = False) -> bytes:
+                original_read = getattr(wrapped_read, "original_read")
+                for breakpoint in getattr(wrapped_read, "breakpoints"):
+                    if (offset <= breakpoint) and (breakpoint < offset + length):
+                        import pdb
+
+                        pdb.set_trace()
+                        print("Hit breakpoint")
+                return original_read(offset, length, pad)
+
+            setattr(wrapped_read, "breakpoints", set())
+            setattr(wrapped_read, "original_read", layer.read)
+            setattr(layer, "read", wrapped_read)
+
+        # Add the new breakpoint
+        breakpoints = getattr(layer.read, "breakpoints")
+        breakpoints.add(address)
+        setattr(layer.read, "breakpoints", breakpoints)
+
 
 class NullFileHandler(io.BytesIO, interfaces.plugins.FileHandlerInterface):
     """Null FileHandler that swallows files whole without consuming memory"""