SCTP transport (:gen_sctp) when the OTP driver is available.

What problem this solves

Some deployments listen for SCTP over IP directly via OTP's :gen_sctp. This module implements the Transport behaviour for that path: bind, send on stream 0, and normalize {:sctp, ...} messages.

Not WebRTC SCTP-over-DTLS; see SctpAssociation for the sans-IO path used with DTLS application data.

accept/2 always returns {:error, :sctp_not_supported} because associations arrive as messages on the listen socket and cannot be driven by Acceptor's accept loop.

iex> Xirsys.Sockets.Transport.SCTP.framing()
:datagram
iex> Xirsys.Sockets.Transport.SCTP.handle_message({:sctp, :sock, {127, 0, 0, 1}, 9, [], "hi"}, :sock)
{:data, "hi", {{127, 0, 0, 1}, 9}}
iex> Xirsys.Sockets.Transport.SCTP.handle_message({:sctp_closed, :sock}, :sock)
{:closed, :normal}

RFCs

• RFC 4960 - SCTP (streams, associations)