From 8fa666b75d47ead50be208c9b05034fd09725d7f Mon Sep 17 00:00:00 2001
From: HD Moore <hd_moore@rapid7.com>
Date: Sun, 28 Sep 2014 17:41:21 -0700
Subject: [PATCH] Verbose messages on why a connection is closed

---
 lib/msf/core/exploit/smb.rb | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/lib/msf/core/exploit/smb.rb b/lib/msf/core/exploit/smb.rb
index 85b1bfc07f..587d716c98 100644
--- a/lib/msf/core/exploit/smb.rb
+++ b/lib/msf/core/exploit/smb.rb
@@ -760,13 +760,15 @@ module Exploit::Remote::SMBServer
     # Handle any number of errors that a read can trigger depending on socket state
     rescue ::IOError, ::EOFError, 
       ::Errno::ECONNRESET, ::Errno::ENOTCONN, ::Errno::ECONNABORTED, 
-      ::Errno::ETIMEDOUT, ::Errno::ENETRESET, ::Errno::ESHUTDOWN 
+      ::Errno::ETIMEDOUT, ::Errno::ENETRESET, ::Errno::ESHUTDOWN
+      vprint_status("Dropping connection from #{smb[:name]} due to exception: #{$!.class} #{$!}")
       smb_stop(c)
       return
     end
 
     # The client said it had data, but lied, kill the session
     unless buff and buff.length > 0
+      vprint_status("Dropping connection from #{smb[:name]} due to empty payload...")
       smb_stop(c)
       return
     end
@@ -776,6 +778,7 @@ module Exploit::Remote::SMBServer
 
     # Prevent a simplistic DoS if the buffer is too big
     if smb[:data].length > (1024*1024*datastore['SMBServerMaximumBuffer'])
+      vprint_status("Dropping connection from #{smb[:name]} due to oversized buffer of #{smb[:data].length} bytes...")
       smb_stop(c)
       return
     end
@@ -823,10 +826,11 @@ module Exploit::Remote::SMBServer
       pkt = CONST::SMB_BASE_PKT.make_struct
       pkt.from_s(buff)
 
-      # Only response to requests, ignore server replies
+      # Only respond to requests, ignore server replies
       if (pkt['Payload']['SMB'].v['Flags1'] & 128 != 0)
-        print_status("Ignoring server response from #{smb[:name]}")
-        next
+        vprint_status("Dropping connection from #{smb[:name]} due to missing client request flag")
+        smb_stop(c)
+        return
       end
 
       cmd = pkt['Payload']['SMB'].v['Command']
@@ -895,7 +899,10 @@ module Exploit::Remote::SMBServer
       end
 
       # Purge any idle connections to rescue file descriptors
-      purge_list.each { |sc| smb_stop(sc) }
+      purge_list.each do |sc|
+        vprint_status("Dropping connection from #{@state[sc][:name]} due to idle timeout...")
+        smb_stop(sc)
+      end
     end
   end