Function sctp_queue_data_to_stream

freebsd/netinet/sctp_indata.c:480–630

* Queue the chunk either right into the socket buffer if it is the next one * to go OR put it in the correct place in the delivery queue. If we do * append to the so_buf, keep doing so until we are out of order as * long as the control's entered are non-fragmented. */

 * long as the control's entered are non-fragmented.
 */
static void
sctp_queue_data_to_stream(struct sctp_tcb *stcb,
    struct sctp_association *asoc,
    struct sctp_queued_to_read *control, int *abort_flag, int *need_reasm)
{
	/*
	 * FIX-ME maybe? What happens when the ssn wraps? If we are getting
	 * all the data in one stream this could happen quite rapidly. One
	 * could use the TSN to keep track of things, but this scheme breaks
	 * down in the other type of stream usage that could occur. Send a
	 * single msg to stream 0, send 4Billion messages to stream 1, now
	 * send a message to stream 0. You have a situation where the TSN
	 * has wrapped but not in the stream. Is this worth worrying about
	 * or should we just change our queue sort at the bottom to be by
	 * TSN.
	 *
	 * Could it also be legal for a peer to send ssn 1 with TSN 2 and
	 * ssn 2 with TSN 1? If the peer is doing some sort of funky TSN/SSN
	 * assignment this could happen... and I don't see how this would be
	 * a violation. So for now I am undecided an will leave the sort by
	 * SSN alone. Maybe a hybred approach is the answer
	 *
	 */
	struct sctp_queued_to_read *at;
	int queue_needed;
	uint32_t nxt_todel;
	struct mbuf *op_err;
	struct sctp_stream_in *strm;
	char msg[SCTP_DIAG_INFO_LEN];

	strm = &asoc->strmin[control->sinfo_stream];
	if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
		sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_INTO_STRD);
	}
	if (SCTP_MID_GT((asoc->idata_supported), strm->last_mid_delivered, control->mid)) {
		/* The incoming sseq is behind where we last delivered? */
		SCTPDBG(SCTP_DEBUG_INDATA1, "Duplicate S-SEQ: %u delivered: %u from peer, Abort association\n",
		    strm->last_mid_delivered, control->mid);
		/*
		 * throw it in the stream so it gets cleaned up in
		 * association destruction
		 */
		TAILQ_INSERT_HEAD(&strm->inqueue, control, next_instrm);
		if (asoc->idata_supported) {
			SCTP_SNPRINTF(msg, sizeof(msg), "Delivered MID=%8.8x, got TSN=%8.8x, SID=%4.4x, MID=%8.8x",
			    strm->last_mid_delivered, control->sinfo_tsn,
			    control->sinfo_stream, control->mid);
		} else {
			SCTP_SNPRINTF(msg, sizeof(msg), "Delivered SSN=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
			    (uint16_t)strm->last_mid_delivered,
			    control->sinfo_tsn,
			    control->sinfo_stream,
			    (uint16_t)control->mid);
		}
		op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
		stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_2;
		sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
		*abort_flag = 1;