rapid7/metasploit-framework — pull request #4165 by jhart-r7 (2014-11-10 18:18:48+00:00)
Title: Check for INTERFACE or SMAC in dtp setup

The module requires one of these to be set, otherwise you get failures like:

```
[-] Auxiliary failed: TypeError wrong argument type nil (expected String)
[-] Call stack:
[-] /home/jhart/labs/git/metasploit-framework/lib/msf/core/exploit/capture.rb:478:in `addresses'
[-] /home/jhart/labs/git/metasploit-framework/lib/msf/core/exploit/capture.rb:478:in `get_mac'
[-] /home/jhart/labs/git/metasploit-framework/modules/auxiliary/spoof/cisco/dtp.rb:59:in `smac'
[-] /home/jhart/labs/git/metasploit-framework/modules/auxiliary/spoof/cisco/dtp.rb:64:in `run'
```

## Validation

- [ ] Use module before this PR, confirming that it fails when neither ```INTERFACE``` or ```SMAC``` are set
- [ ] Use module before this PR, confirming that it works properly when either ```INTERFACE``` or ```SMAC``` are set
- [ ] Use this module after this PR, confirming that the failure is more sane when ```INTERFACE``` or ```SMAC``` are not set