Fixed module dependency bug

src/binwalk/core/common.py

@@ -261,9 +261,11 @@ class BlockFile(BLOCK_FILE_PARENT_CLASS):
 
 		if block > 0:
 			self.READ_BLOCK_SIZE = block
+		self.base_block_size = self.READ_BLOCK_SIZE
 			
 		if trail > 0:
 			self.MAX_TRAILING_SIZE = trail
+		self.base_trail_size = self.MAX_TRAILING_SIZE
 
 		super(self.__class__, self).__init__(fname, mode)
 
@@ -297,8 +299,15 @@ class BlockFile(BLOCK_FILE_PARENT_CLASS):
 		return data
 
 	def reset(self):
+		self.set_block_size(block=self.base_trail_size, trail=self.base_trail_size)
 		self.seek(self.offset)
 
+	def set_block_size(self, block=0, trail=0):
+		if block is not None:
+			self.READ_BLOCK_SIZE = block
+		if trail is not None:
+			self.MAX_TRAILING_SIZE = trail
+
 	def write(self, data):
 		'''
 		Writes data to the opened file.

src/binwalk/core/module.py

@@ -543,8 +543,6 @@ class Modules(object):
 		# If the module is not being loaded as a dependency, add it to the loaded modules dictionary
 		if not dependency:
 			self.loaded_modules[module] = obj
-		if not kwargs and not has_key(self.default_dependency_modules, module):
-			self.default_dependency_modules[module] = obj
 
 		return obj
 			
@@ -572,18 +570,14 @@ class Modules(object):
 				if dependency.module == module:
 					continue
 
-				# Only honor custom kwargs from modules that are enabled, else madness ensues.
+				# Only load dependencies with custom kwargs from modules that are enabled, else madness ensues.
 				# Example: Heursitic module depends on entropy module, and sets entropy kwargs to contain 'enabled' : True.
 				#          Without this check, an entropy scan would always be run, even if -H or -E weren't specified!
-				if module_enabled:
-					kwargs = dependency.kwargs
-				else:
-					kwargs = {}
-				
-				if not kwargs and has_key(self.default_dependency_modules, dependency.module):
-					depobj = self.default_dependency_modules[dependency.module]
-				else:
-					depobj = self.run(dependency.module, dependency=True, kwargs=kwargs)
+				#
+				# Modules that are not enabled (e.g., extraction module) can load any dependency as long as they don't
+				# set any custom kwargs for those dependencies.
+				if module_enabled or not dependency.kwargs:
+					depobj = self.run(dependency.module, dependency=True, kwargs=dependency.kwargs)
 			
 				# If a dependency failed, consider this a non-recoverable error and raise an exception
 				if depobj.errors:

src/binwalk/modules/configuration.py

@@ -152,7 +152,7 @@ class Configuration(Module):
 		if len(self.target_files) > 1 and not self.verbose:
 			self.verbose = True
 
-	def open_file(self, fname, length=None, offset=None, swap=None):
+	def open_file(self, fname, length=None, offset=None, swap=None, block=0, trail=0):
 		'''
 		Opens the specified file with all pertinent configuration settings.
 		'''
@@ -163,7 +163,7 @@ class Configuration(Module):
 		if swap is None:
 			swap = self.swap_size
 
-		return binwalk.core.common.BlockFile(fname, length=length, offset=offset, swap=swap)
+		return binwalk.core.common.BlockFile(fname, length=length, offset=offset, swap=swap, block=block, trail=trail)
 
 	def _open_target_files(self):
 		'''

src/binwalk/modules/signature.py

@@ -98,7 +98,7 @@ class Signature(Module):
 				break
 
 			current_block_offset = 0
-			block_start = fp.offset + fp.total_read - dlen
+			block_start = fp.offset + fp.tell() - dlen
 			self.status.completed = block_start - fp.offset
 
 			for candidate_offset in self.parser.find_signature_candidates(data, dlen):