Hi Wei If I can't take that without a patch that processes SHUTDOWN chunks in SHUTDOWN_RECEIVED state. The problem is that if B in your example has more data to send, it will ignore subsequent SHUTDOWN chunks. If A uses only SHUTDOWNS to acknowledge data, then this would results us ignoring acks and retransmitting and eventually ABORTING the association. -vlad Wei Yongjun wrote: > If SHUTDOWN is received in SHUTDOWN-PENDING state, enpoint should enter > the SHUTDOWN-RECEIVED state and check the Cumulative TSN Ack field of > the SHUTDOWN chunk (RFC 4960 Section 9.2). If the SHUTDOWN chunk can > acknowledge all of the send DATA chunks, SHUTDOWN-ACK should be sent. > > But now endpoint just silently discarded the SHUTDOWN chunk. > > SHUTDOWN received in SHUTDOWN-PENDING state can happend when the last > SACK is lost by network, or the SHUTDOWN chunk can acknowledge all of > the received DATA chunks. The packet sequence(SACK lost) is like this: > > Endpoint A Endpoint B ULP > (ESTABLISHED) (ESTABLISHED) > > <----------- DATA > <--- shutdown > Enter SHUTDOWN-PENDING state > SACK ----lost----> > > SHUTDOWN(*1) ------------> > > <----------- SHUTDOWN-ACK > > (*1) silently discarded now. > > This patch fix to handle SHUTDOWN in SHUTDOWN-PENDING state as the same > as ESTABLISHED state. > > Signed-off-by: Wei Yongjun <yjwei@xxxxxxxxxxxxxx> > --- > net/sctp/sm_statetable.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c > index dd4ddc4..a5b5590 100644 > --- a/net/sctp/sm_statetable.c > +++ b/net/sctp/sm_statetable.c > @@ -266,7 +266,7 @@ const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t event_type, > /* SCTP_STATE_ESTABLISHED */ \ > TYPE_SCTP_FUNC(sctp_sf_do_9_2_shutdown), \ > /* SCTP_STATE_SHUTDOWN_PENDING */ \ > - TYPE_SCTP_FUNC(sctp_sf_discard_chunk), \ > + TYPE_SCTP_FUNC(sctp_sf_do_9_2_shutdown), \ > /* SCTP_STATE_SHUTDOWN_SENT */ \ > TYPE_SCTP_FUNC(sctp_sf_do_9_2_shutdown_ack), \ > /* SCTP_STATE_SHUTDOWN_RECEIVED */ \ -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
