Add file_stat to linux shell sessions

[pingport80]

Summary

This PR adds FileStat class for linux systems which can be used to create a stat object containing information about a specific file similar to stat in meterpreter file system API.

Verification Steps

>> passwd = stat('/etc/passwd')
=> 
#<FileStat:0x00007fa2120db4f0
...
>> passwd.size
=> 2809
>> passwd.setuid?
=> false
>> passwd.atime
=> 2021-05-24 19:52:01.071081298 +0530
>> passwd.dev
=> 66309
>> passwd.ctime
=> 2021-04-03 14:55:18.615202365 +0530
>> passwd.mtime
=> 2021-04-03 14:55:18.611202365 +0530

>> mount = stat('/bin/mount')
=> 
#<FileStat:0x0000555af0a18fd8
...
>> mount.setuid?
=> true
>> mount.file?
=> true
>> mount.directory?
=> false
>> mount.symlink?
=> false
>> mount.socket?
=> false
>> mount.pipe?
=> false
>> mount.chardev?
=> false
>> mount.blockdev?
=> false

[smcintyre-r7]

Changes look good to me! I tested a Windows Meterpreter, Windows shell, Python Meterpreter on Linux and a Linux shell session.

Each one behaved as I would expect. The exception in the output is due to Windows shell sessions not being supported yet which is fine since it raises a NotImplementedError.

Testing Output

msf6 post(windows/gather/credentials/gpp) > irb
[*] You are in post/windows/gather/credentials/gpp
irb: warn: can't alias ls from irb_ls.
>> stat('C:\\Users')
=> #<#<Class:0x00007f07a47ee0c0>:0x00000000087d4cd8 @stathash={"st_dev"=>0, "st_mode"=>16749, "st_nlink"=>0, "st_uid"=>0, "st_gid"=>0, "st_rdev"=>0, "st_ino"=>0, "st_size"=>4096, "st_atime"=>1622225745, "st_mtime"=>1585758963, "st_ctime"=>1536991766}>
>> exit
msf6 post(windows/gather/credentials/gpp) > set SESSION 2
SESSION => 2
[*] Starting IRB shell...
[*] You are in post/windows/gather/credentials/gpp

>> stat('C:\\Users')
Traceback (most recent call last):
	25: from ./msfconsole:23:in `<main>'
	24: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/metasploit/framework/command/base.rb:82:in `start'
	23: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/metasploit/framework/command/console.rb:48:in `start'
	22: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/rex/ui/text/shell.rb:157:in `run'
	21: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/rex/ui/text/dispatcher_shell.rb:475:in `run_single'
	20: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/rex/ui/text/dispatcher_shell.rb:475:in `each'
	19: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/rex/ui/text/dispatcher_shell.rb:481:in `block in run_single'
	18: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/rex/ui/text/dispatcher_shell.rb:532:in `run_command'
	17: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/msf/ui/console/command_dispatcher/developer.rb:116:in `cmd_irb'
	16: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/rex/ui/text/irb_shell.rb:52:in `run'
	15: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/rex/ui/text/irb_shell.rb:52:in `catch'
	14: from /home/smcintyre/Repositories/metasploit-framework.pr/lib/rex/ui/text/irb_shell.rb:53:in `block in run'
	 1: from (irb):1:in `<main>'
/home/smcintyre/Repositories/metasploit-framework.pr/lib/msf/core/post/file.rb:691:in `stat': NotImplementedError (NotImplementedError)
>> exit
msf6 post(windows/gather/credentials/gpp) > set SESSION 3
SESSION => 3
msf6 post(windows/gather/credentials/gpp) > irb
[*] Starting IRB shell...
[*] You are in post/windows/gather/credentials/gpp

>> stat('/etc')
=> #<#<Class:0x0000000009044558>:0x0000000005916ab8 @stathash={"st_dev"=>64768, "st_mode"=>16877, "st_nlink"=>190, "st_uid"=>0, "st_gid"=>0, "st_rdev"=>0, "st_ino"=>1441793, "st_size"=>12288, "st_atime"=>1622205354, "st_mtime"=>1622205328, "st_ctime"=>1622205328}>
>> exit
msf6 post(windows/gather/credentials/gpp) > set SESSION 4
SESSION => 4
msf6 post(windows/gather/credentials/gpp) > irb
[*] Starting IRB shell...
[*] You are in post/windows/gather/credentials/gpp

>> stat('/etc/')
=> #<Msf::Post::File::FileStat:0x00007f07a5380960 @stathash={"st_dev"=>64768, "st_ino"=>1441793, "st_nlink"=>190, "st_uid"=>0, "st_gid"=>0, "st_rdev"=>0, "st_size"=>12288, "st_blksize"=>512, "st_blocks"=>4096, "st_atime"=>1622205354, "st_mtime"=>1622205328, "st_ctime"=>1622205328, "st_mode"=>16877}>
>> 

[smcintyre-r7]

Release Notes

Added support for obtaining a stat object from the Post API via shell sessions when the stat command is available.