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Commit ea2dfb37 authored by Vlad Yasevich's avatar Vlad Yasevich
Browse files

SCTP: properly clean up fragment and ordering queues during FWD-TSN. 



When we recieve a FWD-TSN (meaning the peer has abandoned the data),
we need to clean up any partially received messages that may be
hanging out on the re-assembly or re-ordering queues.  This is
a MUST requirement that was not properly done before.

Signed-off-by: default avatarVlad Yasevich <vladislav.yasevich@hp.com.>
parent b07d68b5

include/net/sctp/ulpqueue.h

+1 −0
Original line number Diff line number Diff line
@@ -83,6 +83,7 @@ int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc); 
/* Skip over an SSN. */

void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn);



void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *, __u32);

#endif /* __sctp_ulpqueue_h__ */

net/sctp/sm_sideeffect.c

+3 −0
Original line number Diff line number Diff line
@@ -1130,6 +1130,9 @@ static int sctp_cmd_interpreter(sctp_event_t event_type, 
			/* Move the Cumulattive TSN Ack ahead. */

			sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);



			/* purge the fragmentation queue */

			sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);



			/* Abort any in progress partial delivery. */

			sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);

			break;

net/sctp/ulpqueue.c

+62 −13
Original line number Diff line number Diff line
@@ -659,6 +659,46 @@ done: 
	return retval;

}



/*

 * Flush out stale fragments from the reassembly queue when processing

 * a Forward TSN.

 *

 * RFC 3758, Section 3.6

 *

 * After receiving and processing a FORWARD TSN, the data receiver MUST

 * take cautions in updating its re-assembly queue.  The receiver MUST

 * remove any partially reassembled message, which is still missing one

 * or more TSNs earlier than or equal to the new cumulative TSN point.

 * In the event that the receiver has invoked the partial delivery API,

 * a notification SHOULD also be generated to inform the upper layer API

 * that the message being partially delivered will NOT be completed.

 */

void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn)

{

	struct sk_buff *pos, *tmp;

	struct sctp_ulpevent *event;

	__u32 tsn;



	if (skb_queue_empty(&ulpq->reasm))

		return;



	skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {

		event = sctp_skb2event(pos);

		tsn = event->tsn;



		/* Since the entire message must be abandoned by the

		 * sender (item A3 in Section 3.5, RFC 3758), we can

		 * free all fragments on the list that are less then

		 * or equal to ctsn_point

		 */

		if (TSN_lte(tsn, fwd_tsn)) {

			__skb_unlink(pos, &ulpq->reasm);

			sctp_ulpevent_free(event);

		} else

			break;

	}

}



/* Helper function to gather skbs that have possibly become

 * ordered by an an incoming chunk.

 */
@@ -794,7 +834,7 @@ static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, 
/* Helper function to gather skbs that have possibly become

 * ordered by forward tsn skipping their dependencies.

 */

static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq)

static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)

{

	struct sk_buff *pos, *tmp;

	struct sctp_ulpevent *cevent;
@@ -813,31 +853,40 @@ static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq) 
		csid = cevent->stream;

		cssn = cevent->ssn;



		if (cssn != sctp_ssn_peek(in, csid))

		/* Have we gone too far?  */

		if (csid > sid)

			break;



		/* Found it, so mark in the ssnmap. */

		sctp_ssn_next(in, csid);

		/* Have we not gone far enough?  */

		if (csid < sid)

			continue;



		/* see if this ssn has been marked by skipping */

		if (!SSN_lt(cssn, sctp_ssn_peek(in, csid)))

			break;



		__skb_unlink(pos, &ulpq->lobby);

		if (!event) {

		if (!event)

			/* Create a temporary list to collect chunks on.  */

			event = sctp_skb2event(pos);

			__skb_queue_tail(&temp, sctp_event2skb(event));

		} else {



		/* Attach all gathered skbs to the event.  */

		__skb_queue_tail(&temp, pos);

	}

	}



	/* Send event to the ULP.  'event' is the sctp_ulpevent for

	 * very first SKB on the 'temp' list.

	 */

	if (event)

	if (event) {

		/* see if we have more ordered that we can deliver */

		sctp_ulpq_retrieve_ordered(ulpq, event);

		sctp_ulpq_tail_event(ulpq, event);

	}

}



/* Skip over an SSN. */

/* Skip over an SSN. This is used during the processing of

 * Forwared TSN chunk to skip over the abandoned ordered data

 */

void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)

{

	struct sctp_stream *in;
@@ -855,7 +904,7 @@ void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) 
	/* Go find any other chunks that were waiting for

	 * ordering and deliver them if needed.

	 */

	sctp_ulpq_reap_ordered(ulpq);

	sctp_ulpq_reap_ordered(ulpq, sid);

	return;

}