From: Xin Long <lucien.xin@gmail.com>
Date: Mon,  2 Mar 2020 14:57:15 +0800

As it says in rfc6458#section-9.2:

  The application uses the sctp_peeloff() call to branch off an
  association into a separate socket.  (Note that the semantics are
  somewhat changed from the traditional one-to-one style accept()
  call.)  Note also that the new socket is a one-to-one style socket.
  Thus, it will be confined to operations allowed for a one-to-one
  style socket.

Prior to this patch, sctp_peeloff() returned a one-to-many type socket,
on which some operations are not allowed, like shutdown, as Jere
reported.

This patch is to change it to return a one-to-one type socket instead.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Leppanen, Jere (Nokia - FI/Espoo) <redacted>
Signed-off-by: Xin Long <lucien.xin@gmail.com>

I don't know what to do with this patch.

There seems to be some discussion about a potential alternative approach
to the fix, but there were problems with that suggestion.

Please advise, thank you.