Re: defying original 4.3BSD sockets constraint

On Sat, Apr 18, 2026 at 11:09:01AM -0700, Gleb Smirnoff wrote:
T> 1) Stealer uses UDP socket.  TCP bypasses the check since 4658dc8325e03.
T> 2) Stealer does bind(2) and connect(2) to a remote peer.  It needs to know
T>    what port the victim is going to use in the future and what peer it is
T>    going to steal from.
T> 3) Victim creates socket and does bind(2).  Before it would get EADDRINUSE,
T>    now it would succeed and stealer would be able to steal traffic from peer.

Observation on Linux.  There it is even more restrictive, even if the stealing
socket belongs to the same user, and the socket to be bind(2) has SO_REUSEADDR
set, the bind(2) would still fail.  Our current code allows that.

-- 
Gleb Smirnoff