From: James Stanley <james () incoherency co uk>
Date: Wed, 24 Aug 2022 20:32:39 +0100
I have submitted a pull request on github:
https://github.com/nmap/nmap/pull/2510
The summary is: Previously, |netexec()| would cease all communication as soon as it read EOF from either the child proces *or* the remote side. This meant (for example)
when the other end of the TCP socket calls |shutdown(fd, SHUT_WR)|, the
child
process doesn't get a chance to send any more response, drain its
buffers, etc.
The new behaviour is to propagate EOF onwards from the child process to the
remote, and vice versa, and keep a flag variable for each side to say
whether
we still want to be reading from that side. ------------------------------------------------------------------------ With the new version, if you do something like:
|server$ ncat -l 10000 -e /bin/cat client$ ncat localhost 10000 <file1
>file2 |
Then it will now do what you expect: copy |file1| to |file2|. Previously
ncat would stop reading from |/bin/cat| as soon as it got the
half-duplex shutdown from the remote side, which means unless |cat|'s
buffer is empty at the time ncat receives the shutdown, |file2| ends up
shorter than |file1| because of the data stuck inside |cat| that never
got transmitted over the network. Hope that makes sense.
Regards, James Stanley
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- ncat: perform half-duplex shutdown upon EOF James Stanley (Sep 12)
