Fixed IDA offset/length bugs; added binwalk.execute function; updated example scripts

setup.py

@@ -149,7 +149,7 @@ if os.getenv("BUILD_PYQTGRAPH") == "1":
 
 # Install the module, script, and support files
 setup(name = MODULE_NAME,
-      version = "2.0.0",
+      version = "2.1.0",
       description = "Firmware analysis tool",
       author = "Craig Heffner",
       url = "https://github.com/devttys0/%s" % MODULE_NAME,

src/binwalk/__init__.py

-__all__ = ['Modules', 'ModuleException']
+__all__ = ['execute', 'Modules', 'ModuleException']
 
 import sys
 import binwalk.core.common
@@ -8,3 +8,6 @@ import binwalk.core.common
 sys.path.append(binwalk.core.common.get_libs_path())
 
 from binwalk.core.module import Modules, ModuleException
+
+def execute(*args, **kwargs):
+    return Modules(*args, **kwargs).execute()

src/binwalk/core/common.py

@@ -176,6 +176,12 @@ def strings(filename, minimum=4):
                 else:
                     result = ""
 
+class GenericContainer(object):
+
+    def __init__(self, **kwargs):
+        for (k,v) in iterator(kwargs):
+            setattr(self, k, v)
+
 class MathExpression(object):
     '''
     Class for safely evaluating mathematical expressions from a string.
@@ -268,52 +274,66 @@ class BlockFile(BLOCK_FILE_PARENT_CLASS):
         Returns None.
         '''
         self.total_read = 0
-        self.swap_size = swap
         self.block_read_size = self.DEFAULT_BLOCK_READ_SIZE
         self.block_peek_size = self.DEFAULT_BLOCK_PEEK_SIZE
 
+        # This is so that custom parent classes can access/modify arguments as necessary
+        self.args = GenericContainer(fname=fname,
+                                     mode=mode,
+                                     length=length,
+                                     offset=offset,
+                                     block=block,
+                                     peek=peek,
+                                     swap=swap,
+                                     size=0)
+
         # Python 2.6 doesn't like modes like 'rb' or 'wb'
-        mode = mode.replace('b', '')
+        mode = self.args.mode.replace('b', '')
 
-        try:
-            self.size = file_size(fname)
-        except KeyboardInterrupt as e:
-            raise e
-        except Exception:
-            self.size = 0
-
-        if offset < 0:
-            self.offset = self.size + offset
+        super(self.__class__, self).__init__(fname, mode)
+
+        self.swap_size = self.args.swap
+        
+        if self.args.size:
+            self.size = self.args.size
         else:
-            self.offset = offset
+            try:
+                self.size = file_size(self.args.fname)
+            except KeyboardInterrupt as e:
+                raise e
+            except Exception:
+                self.size = 0
+
+        if self.args.offset < 0:
+            self.offset = self.size + self.args.offset
+        else:
+            self.offset = self.args.offset
 
         if self.offset < 0:
             self.offset = 0
         elif self.offset > self.size:
             self.offset = self.size
 
-        if offset < 0:
-            self.length = offset * -1
-        elif length:
-            self.length = length
+        if self.args.offset < 0:
+            self.length = self.args.offset * -1
+        elif self.args.length:
+            self.length = self.args.length
         else:
-            self.length = self.size - offset
+            self.length = self.size - self.args.offset
 
         if self.length < 0:
             self.length = 0
         elif self.length > self.size:
             self.length = self.size
 
-        if block is not None:
-            self.block_read_size = block
+        if self.args.block is not None:
+            self.block_read_size = self.args.block
         self.base_block_size = self.block_read_size
             
-        if peek is not None:
-            self.block_peek_size = peek
+        if self.args.peek is not None:
+            self.block_peek_size = self.args.peek
         self.base_peek_size = self.block_peek_size
 
-        super(self.__class__, self).__init__(fname, mode)
-
         # Work around for python 2.6 where FileIO._name is not defined
         try:
             self.name

src/binwalk/core/idb.py

@@ -51,18 +51,22 @@ class IDBFileIO(io.FileIO):
         else:
             self.__idb__ = True
             self.name = fname
+
             self.idb_start = 0
             self.idb_pos = 0
             self.idb_end = end_address()
 
-            if self.size == 0:
-                self.size = end_address() - start_address()
-
-            if self.length == 0:
-                self.length = self.size
-
-            if self.offset == 0:
-                self.offset = start_address()
+            if self.args.size == 0:
+                self.args.size = end_address()
+            
+            if self.args.offset == 0:
+                self.args.offset = start_address()
+            elif self.args.offset < 0:
+                self.args.length = self.args.offset * -1
+                self.args.offset = end_address() + self.args.offset
+
+            if self.args.length == 0 or self.args.length > (end_address() - start_address()):
+                self.args.length = end_address() - start_address()
 
     def read(self, n=-1):
         if not self.__idb__:

src/scripts/examples/binwalk_simple.py

@@ -4,4 +4,4 @@ import binwalk
 
 # Since no options are specified, they are by default taken from sys.argv.
 # Effecitvely, this duplicates the functionality of the normal binwalk script.
-binwalk.Modules().execute()
+binwalk.execute()

src/scripts/examples/signature_scan.py

@@ -5,7 +5,7 @@ import binwalk
 
 try:
     # Perform a signature scan against the files specified on the command line and suppress the usual binwalk output.
-    for module in binwalk.Modules().execute(*sys.argv[1:], signature=True, quiet=True):
+    for module in binwalk.execute(*sys.argv[1:], signature=True, quiet=True):
         print ("%s Results:" % module.name)
         for result in module.results:
             print ("\t%s    0x%.8X    %s" % (result.file.name, result.offset, result.description))