Fix/dns/dot suffixed names

[zeroSteiner]

This fixes an issue that was reported where msfconsole will fail to start if the /etc/hosts file contains a name ending in a . such as bad..

The core of the fix is to upgrade rex-socket from 0.1.56 to 0.1.57, which pulls in the changes from rapid7/rex-socket#66. In addition to that, the #initialize method was updated to ignore errors that may occur when parsing the hosts file so any other issues that occur with it will not prevent msfconsole from starting.

Testing

On a Linux system:

• Edit /etc/hosts and add a new line containing 127.1.1.1 bad.
• Start msfconsole, see that it starts
• Run dns reset-config, see the bad. hostname is defined.

[adfoster-r7]

Is it possible to ignore the individual entries that break? 👀

i.e. If an invalid entry is the first line of the /etc/hosts file, we could ignore that individual host and continue to parse the rest of the file with 127.0.0.1 localhost etc

[adfoster-r7]

Looks like the default @logger is /dev/null:

[11] pry(#<Rex::Proto::DNS::CachedResolver>)> @config[:log_file]
=> "/dev/null"

Which in this scenario might not be useful if folk want to debug issues/report framework issues; Is it possible to wire it up to the framework logging

[adfoster-r7]

Looks good to me to fix the current issues; My comments aren't a blocker/can be circled back to at a future point in time - looks good to merge now - will hand over the reins to you for that 💯

[adfoster-r7]

Release Notes

This fixes an issue that was reported where msfconsole will fail to start if the user's /etc/hosts file contained a host name ending in a . or containing _ characters