As David Laight noticed,
"In a multithreaded program it is reasonable to have a thread blocked in
accept(). With TCP a subsequent shutdown(listen_fd, SHUT_RDWR) causes
the accept to fail. But nothing happens for SCTP."
sctp_disconnect() is eventually called when shutdown a listen socket,
but nothing is done in this function. This patch sets RCV_SHUTDOWN
flag in sk->sk_shutdown there, and adds the check (sk->sk_shutdown &
RCV_SHUTDOWN) to break and return in sctp_accept().
Note that shutdown() is only supported on TCP-style SCTP socket.
Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cda91d5b91