sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const sctp_subtype_t type,
					void *arg,
					sctp_cmd_seq_t *commands)
{
	struct sctp_chunk *chunk = arg;

	if (!sctp_vtag_verify_either(chunk, asoc))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* Make sure that the ABORT chunk has a valid length.
	 * Since this is an ABORT chunk, we have to discard it
	 * because of the following text:
	 * RFC 2960, Section 3.3.7
	 *    If an endpoint receives an ABORT with a format error or for an
	 *    association that doesn't exist, it MUST silently discard it.
	 * Because the length is "invalid", we can't really discard just
	 * as we do not know its true length.  So, to be safe, discard the
	 * packet.
	 */
	if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);

	/* ADD-IP: Special case for ABORT chunks
	 * F4)  One special consideration is that ABORT Chunks arriving
	 * destined to the IP address being deleted MUST be
	 * ignored (see Section 5.3.1 for further details).
	 */
	if (SCTP_ADDR_DEL ==
		    sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
		return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);

	return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
}

Unknown