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Commit a2f36eec authored by Wei Yongjun's avatar Wei Yongjun Committed by Vlad Yasevich
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sctp: drop SHUTDOWN chunk if the TSN is less than the CTSN 



If Cumulative TSN Ack field of SHUTDOWN chunk is less than the
Cumulative TSN Ack Point then drop the SHUTDOWN chunk.

Signed-off-by: default avatarWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: default avatarVlad Yasevich <vladislav.yasevich@hp.com>
parent 9c5c62be

net/sctp/sm_statefuns.c

+15 −1
Original line number Diff line number Diff line
@@ -2570,6 +2570,12 @@ sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep, 
	chunk->subh.shutdown_hdr = sdh;

	ctsn = ntohl(sdh->cum_tsn_ack);



	if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {

		SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);

		SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);

		return SCTP_DISPOSITION_DISCARD;

	}



	/* If Cumulative TSN Ack beyond the max tsn currently

	 * send, terminating the association and respond to the

	 * sender with an ABORT.
@@ -2633,6 +2639,7 @@ sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint *ep, 
{

	struct sctp_chunk *chunk = arg;

	sctp_shutdownhdr_t *sdh;

	__u32 ctsn;



	if (!sctp_vtag_verify(chunk, asoc))

		return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
@@ -2644,12 +2651,19 @@ sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint *ep, 
						  commands);



	sdh = (sctp_shutdownhdr_t *)chunk->skb->data;

	ctsn = ntohl(sdh->cum_tsn_ack);



	if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {

		SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);

		SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);

		return SCTP_DISPOSITION_DISCARD;

	}



	/* If Cumulative TSN Ack beyond the max tsn currently

	 * send, terminating the association and respond to the

	 * sender with an ABORT.

	 */

	if (!TSN_lt(ntohl(sdh->cum_tsn_ack), asoc->next_tsn))

	if (!TSN_lt(ctsn, asoc->next_tsn))

		return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);



	/* verify, by checking the Cumulative TSN Ack field of the