Major cleanups to the session manager, serialized processing of incoming connections, concurrent processing (up to a max scheduler thread count) of meterpreter initialization/scripts. This is to avoid a potential deadlock in openssl and ensure consistent, reliable session staging. This commit also fixes a bug that would mark database sessions as closed too early.

git-svn-id: file:///home/svn/framework3/trunk@12485 4d416f70-5f16-0410-b530-b9f4589650da

lib/msf/base/sessions/meterpreter_options.rb

@@ -25,6 +25,9 @@ module MeterpreterOptions
 	def on_session(session)
 		super
 
+		# Defer the session initialization to the Session Manager scheduler
+		framework.sessions.schedule Proc.new {
+		
 		session.init_ui(self.user_input, self.user_output)
 
 		if (datastore['AutoLoadStdapi'] == true)
@@ -61,6 +64,8 @@ module MeterpreterOptions
 			end
 		end
 		
+		}
+
 	end
 
 end

lib/msf/core/db.rb

@@ -476,20 +476,17 @@ class DBManager
 		ret = {}
 
 		
-		s = Msf::DBManager::Session.create(sess_data)
+		s = Msf::DBManager::Session.new(sess_data)
+		s.save!
+		
 		if opts[:session]
 			session.db_record = s 
-		else
-			myret = s.save!
 		end
-		ret[:session] = s
-		
 
 		# If this is a live session, we know the host is vulnerable to something.
 		# If the exploit used was multi/handler, though, we don't know what
 		# it's vulnerable to, so it isn't really useful to save it.
-		if opts[:session]
-		if session.via_exploit and session.via_exploit != "exploit/multi/handler"
+		if opts[:session] and session.via_exploit and session.via_exploit != "exploit/multi/handler"
 			return unless host
 			port = session.exploit_datastore["RPORT"]
 			service = (port ? host.services.find_by_port(port) : nil)
@@ -516,9 +513,8 @@ class DBManager
 			}
 			framework.db.report_exploit(exploit_info)
 		end
-		end
 
-		ret[:session]
+		s
 	end
 
 	#

lib/msf/core/handler/reverse_tcp.rb

@@ -1,4 +1,5 @@
 require 'rex/socket'
+require 'thread'
 
 module Msf
 module Handler
@@ -55,7 +56,7 @@ module ReverseTcp
 			], Msf::Handler::ReverseTcp)
 
 			
-		self.conn_threads = []
+		self.handler_queue = ::Queue.new
 	end
 
 	#
@@ -131,12 +132,6 @@ module ReverseTcp
 	#
 	def cleanup_handler
 		stop_handler
-
-		# Kill any remaining handle_connection threads that might
-		# be hanging around
-		conn_threads.each { |thr|
-			thr.kill
-		}
 	end
 
 	#
@@ -158,18 +153,21 @@ module ReverseTcp
 				# Increment the has connection counter
 				self.pending_connections += 1
 				
-				# Start a new thread and pass the client connection
-				# as the input and output pipe.  Client's are expected
-				# to implement the Stream interface.
-				conn_threads << framework.threads.spawn("ReverseTcpHandlerSession", false, client) { |client_copy|
-					begin
-						handle_connection(client_copy)
-					rescue ::Exception
-						elog("Exception raised from handle_connection: #{$!}\n\n#{$@.join("\n")}")
-					end
-				}
+				self.handler_queue.push( client )
 			end while true
 		}
+		
+		self.handler_thread = framework.threads.spawn("ReverseTcpHandlerWorker-#{datastore['LPORT']}", false) {
+			while true
+				client = self.handler_queue.pop
+				begin
+					handle_connection(client)
+				rescue ::Exception
+					elog("Exception raised from handle_connection: #{$!}\n\n#{$@.join("\n")}")
+				end
+			end
+		}
+		
 	end
 
 	# 
@@ -182,6 +180,12 @@ module ReverseTcp
 			self.listener_thread = nil
 		end
 
+		# Terminate the handler thread
+		if (self.handler_thread and self.handler_thread.alive? == true)
+			self.handler_thread.kill
+			self.handler_thread = nil
+		end
+		
 		if (self.listener_sock)
 			self.listener_sock.close
 			self.listener_sock = nil
@@ -192,8 +196,8 @@ protected
 
 	attr_accessor :listener_sock # :nodoc:
 	attr_accessor :listener_thread # :nodoc:
-	attr_accessor :conn_threads # :nodoc:
-
+	attr_accessor :handler_thread # :nodoc:
+	attr_accessor :handler_queue # :nodoc:
 end
 
 end

lib/msf/core/session_manager.rb

@@ -1,3 +1,5 @@
+require 'thread'
+
 module Msf
 
 ###
@@ -17,17 +19,25 @@ class SessionManager < Hash
 
 	include Framework::Offspring
 
-	LAST_SEEN_INTERVAL = 2.5 * 60
+	LAST_SEEN_INTERVAL  = 60 * 2.5
+	SCHEDULER_THREAD_COUNT = 5
 	
 	def initialize(framework)
 		self.framework = framework
 		self.sid_pool  = 0
-		self.reaper_thread = framework.threads.spawn("SessionManager", true, self) do |manager|
+		self.mutex = Mutex.new		
+		self.scheduler_queue = ::Queue.new
+		self.initialize_scheduler_threads
+		
+		self.monitor_thread = framework.threads.spawn("SessionManager", true) do
 			last_seen_timer = Time.now.utc
 			begin
-			
 			while true
 
+				#
+				# Process incoming data from all stream-based sessions and queue the
+				# data into the associated ring buffers.
+				#	
 				rings = values.select{|s| s.respond_to?(:ring) and s.ring and s.rstream }
 				ready = ::IO.select(rings.map{|s| s.rstream}, nil, nil, 0.5) || [[],[],[]]
 
@@ -61,34 +71,58 @@ class SessionManager < Hash
 						s.rstream.close rescue nil
 						
 						# Deregister the session
-						manager.deregister(s, "Died from #{e.class}")
+						deregister(s, "Died from #{e.class}")
 					end
 				end
 
+
+				#
+				# TODO: Call the dispatch entry point of each Meterpreter thread instead of
+				#       dedicating specific processing threads to each session
+				#
+							
+				
+				#
 				# Check for closed / dead / terminated sessions
-				manager.values.each do |s|
+				#
+				values.each do |s|
 					if not s.alive?
-						manager.deregister(s, "Died")
+						deregister(s, "Died")
 						wlog("Session #{s.sid} has died")
 						next
 					end
+				end
+				
+				#
+				# Mark all open session as alive every LAST_SEEN_INTERVAL
+				#
+				if (Time.now.utc - last_seen_timer) >= LAST_SEEN_INTERVAL				
+					
+					# Update this timer BEFORE processing the session list, this will prevent
+					# processing time for large session lists from skewing our update interval.
 					
-					next if ((Time.now.utc - last_seen_timer) < LAST_SEEN_INTERVAL)
-					# Update the database entry for this session every 5
-					# minutes, give or take.  This notifies other framework
-					# instances that this session is being maintained.
 					last_seen_timer = Time.now.utc
-					if framework.db.active and s.db_record
-						s.db_record.last_seen = Time.now.utc
-						s.db_record.save
+					values.each do |s|
+						# Update the database entry on a regular basis, marking alive threads
+						# as recently seen.  This notifies other framework instances that this
+						# session is being maintained.		
+						if framework.db.active and s.db_record
+							s.db_record.last_seen = Time.now.utc
+							s.db_record.save
+						end
 					end
 				end
 
+
+				#
 				# Skip the database cleanup code below if there is no database
+				#
 				next if not (framework.db and framework.db.active)
 				
+				#
 				# Clean out any stale sessions that have been orphaned by a dead
-				# framewort instance.
+				# framework instance.
+				#
 				Msf::DBManager::Session.find_all_by_closed_at(nil).each do |db_session|
 					if db_session.last_seen.nil? or ((Time.now.utc - db_session.last_seen) > (2*LAST_SEEN_INTERVAL))
 						db_session.closed_at    = db_session.last_seen || Time.now.utc
@@ -96,17 +130,46 @@ class SessionManager < Hash
 						db_session.save
 					end
 				end				
-				
 			end
 			
+			#
+			# All session management falls apart when any exception is raised to this point. Log it.
+			#
 			rescue ::Exception => e
-				wlog("Exception in reaper thread #{e.class} #{e}")
+				wlog("Exception in monitor thread #{e.class} #{e}")
 				wlog("Call Stack\n#{e.backtrace.join("\n")}", 'core', LEV_3)
 			end
-
 		end
 	end
 	
+	#
+	# Dedicated worker threads for pulling data out of new sessions
+	#
+	def initialize_scheduler_threads
+		self.scheduler_threads = []
+		1.upto(SCHEDULER_THREAD_COUNT) do |i|
+			self.scheduler_threads << framework.threads.spawn("SessionScheduler-#{i}", true) do
+				while true
+					item = self.scheduler_queue.pop
+					begin
+						item.call()
+					rescue ::Exception => e
+						wlog("Exception in scheduler thread #{e.class} #{e}")
+						wlog("Call Stack\n#{e.backtrace.join("\n")}", 'core', LEV_3)
+					end
+				end
+			end
+		end
+	end
+	
+	#
+	# Add a new task to the loader thread queue. Task is assumed to be
+	# a Proc or another object that responds to call()
+	#
+	def schedule(task)
+		self.scheduler_queue.push(task)
+	end
+
 	#
 	# Enumerates the sorted list of keys.
 	#
@@ -138,7 +201,7 @@ class SessionManager < Hash
 			return nil
 		end
 
-		next_sid = (self.sid_pool += 1)
+		next_sid = allocate_sid
 		
 		# Initialize the session's sid and framework instance pointer
 		session.sid       = next_sid
@@ -152,7 +215,6 @@ class SessionManager < Hash
 			# Notify the framework that we have a new session opening up...
 			# Don't let errant event handlers kill our session
 			begin
-
 				framework.events.on_session_open(session)
 			rescue ::Exception => e
 				wlog("Exception in on_session_open event handler: #{e.class}: #{e}")
@@ -204,10 +266,22 @@ class SessionManager < Hash
 		return self[sid.to_i]
 	end
 	
+	#
+	# Allocates the next Session ID
+	#
+	def allocate_sid
+		self.mutex.synchronize do
+			self.sid_pool += 1
+		end
+	end
+
 protected
 
 	attr_accessor :sid_pool, :sessions # :nodoc:
-	attr_accessor :reaper_thread # :nodoc:
+	attr_accessor :monitor_thread # :nodoc:
+	attr_accessor :scheduler_threads # :nodoc:
+	attr_accessor :scheduler_queue # :nodoc:
+	attr_accessor :mutex # :nodoc: 
 
 end