Minor improvements and corner case bug fixes to session handling. This fixes issues that can come up when a stream is shut down

git-svn-id: file:///home/svn/framework3/trunk@11371 4d416f70-5f16-0410-b530-b9f4589650da

lib/msf/base/sessions/command_shell.rb

@@ -119,15 +119,15 @@ class CommandShell
 		shell_write(cmd + "\n")
 
 		timeo = 5
-		etime = Time.now.to_f + timeo
+		etime = ::Time.now.to_f + timeo
 		buff = ""
 		
 		# Keep reading data until no more data is available or the timeout is 
 		# reached. 
-		while (Time.now.to_f < etime and ::IO.select([rstream], nil, nil, timeo))
+		while (::Time.now.to_f < etime and ::IO.select([rstream], nil, nil, timeo))
 			res = shell_read(-1, 0.01)
 			buff << res if res
-			timeo = etime - Time.now.to_f
+			timeo = etime - ::Time.now.to_f
 		end
 
 		buff
@@ -146,7 +146,7 @@ class CommandShell
 
 		# Read until we get the data between two tokens or absolute timeout.
 		begin
-			Timeout::timeout(timeout) do
+			::Timeout.timeout(timeout) do
 				buf = ''
 				idx = nil
 				loop do

lib/msf/core/handler/reverse_tcp.rb

@@ -152,7 +152,7 @@ module ReverseTcp
 					client = self.listener_sock.accept	
 				rescue
 					wlog("Exception raised during listener accept: #{$!}\n\n#{$@.join("\n")}")
-					return nil
+					break
 				end
 
 				# Increment the has connection counter

lib/rex/io/stream_abstraction.rb

@@ -126,21 +126,32 @@ protected
 				closed = false
 				buf    = nil
 
+				if not self.rsock
+					wlog("monitor_rsock: the remote socket is nil, exiting loop")
+					break
+				end
+
 				begin
 					s = Rex::ThreadSafe.select( [ self.rsock ], nil, nil, 0.2 )
 					if( s == nil || s[0] == nil )
 						next
 					end
 				rescue Exception => e
+					wlog("monitor_rsock: exception during select: #{e.class} #{e}")
 					closed = true
 				end
 
 				if( closed == false )
 					begin
 						buf = self.rsock.sysread( 32768 )
-						closed = true if( buf == nil )
-					rescue
+						if buf == nil
 							closed = true
+							wlog("monitor_rsock: closed remote socket due to nil read")
+						end
+
+					rescue ::Exception
+						closed = true
+						wlog("monitor_rsock: exception during read: #{e.class} #{e}")						
 					end
 				end
 
@@ -161,14 +172,15 @@ protected
 							end
 						rescue ::IOError => e
 							closed = true
+							wlog("monitor_rsock: exception during write: #{e.class} #{e}")
 							break
 						end
 					end
 				end
 
 				if( closed )
-					self.close_write
-					::Thread.exit
+					self.close_write if self.respond_to?('close_write')
+					break
 				end
 			end
 		}