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authorWei Yongjun <yjwei@cn.fujitsu.com>2008-10-23 04:00:21 -0400
committerDavid S. Miller <davem@davemloft.net>2008-10-23 04:00:21 -0400
commitdf10eec476f2045a2ef5f85d97c7b47d992d7f7b (patch)
tree22d7855af143100359be8ef568f85dd3fb1d636b /net/sctp/sm_statefuns.c
parent91bd6b1e030266cf87d3f567b49f0fa60a7318ba (diff)
sctp: Add check for the TSN field of the SHUTDOWN chunk
If SHUTDOWN chunk is received Cumulative TSN Ack beyond the max tsn currently send, SHUTDOWN chunk be accepted and the association will be broken. New data is send, but after received SACK it will be drop because TSN in SACK is less than the Cumulative TSN, data will be retrans again and again even if correct SACK is received. The packet sequence is like this: Endpoint A Endpoint B ULP (ESTABLISHED) (ESTABLISHED) <----------- DATA (TSN=x-1) <----------- DATA (TSN=x) SHUTDOWN -----------> (Now Cumulative TSN=x+1000) (TSN=x+1000) <----------- DATA (TSN=x+1) SACK -----------> drop the SACK (TSN=x+1) <----------- DATA (TSN=x+1)(retrans) This patch fix this problem by terminating the association and respond to the sender with an ABORT. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp/sm_statefuns.c')
-rw-r--r--net/sctp/sm_statefuns.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index d4c3fbc4671e..12f62174f4a1 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -2544,6 +2544,7 @@ sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2544 sctp_shutdownhdr_t *sdh; 2544 sctp_shutdownhdr_t *sdh;
2545 sctp_disposition_t disposition; 2545 sctp_disposition_t disposition;
2546 struct sctp_ulpevent *ev; 2546 struct sctp_ulpevent *ev;
2547 __u32 ctsn;
2547 2548
2548 if (!sctp_vtag_verify(chunk, asoc)) 2549 if (!sctp_vtag_verify(chunk, asoc))
2549 return sctp_sf_pdiscard(ep, asoc, type, arg, commands); 2550 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
@@ -2558,6 +2559,14 @@ sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2558 sdh = (sctp_shutdownhdr_t *)chunk->skb->data; 2559 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2559 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t)); 2560 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2560 chunk->subh.shutdown_hdr = sdh; 2561 chunk->subh.shutdown_hdr = sdh;
2562 ctsn = ntohl(sdh->cum_tsn_ack);
2563
2564 /* If Cumulative TSN Ack beyond the max tsn currently
2565 * send, terminating the association and respond to the
2566 * sender with an ABORT.
2567 */
2568 if (!TSN_lt(ctsn, asoc->next_tsn))
2569 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
2561 2570
2562 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT 2571 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2563 * When a peer sends a SHUTDOWN, SCTP delivers this notification to 2572 * When a peer sends a SHUTDOWN, SCTP delivers this notification to