sctp: implement the sender side for SACK-IMMEDIATELY extension

This patch implement the sender side for SACK-IMMEDIATELY
extension.

  Section 4.1.  Sender Side Considerations

  Whenever the sender of a DATA chunk can benefit from the
  corresponding SACK chunk being sent back without delay, the sender
  MAY set the I-bit in the DATA chunk header.

  Reasons for setting the I-bit include

  o  The sender is in the SHUTDOWN-PENDING state.

  o  The application requests to set the I-bit of the last DATA chunk
     of a user message when providing the user message to the SCTP
     implementation.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
This commit is contained in:
Wei Yongjun 2009-11-23 15:53:56 -05:00 committed by Vlad Yasevich
parent 6dc7694f9d
commit b93d647174
3 changed files with 22 additions and 1 deletions

View File

@ -206,6 +206,7 @@ enum sctp_sinfo_flags {
SCTP_UNORDERED = 1, /* Send/receive message unordered. */
SCTP_ADDR_OVER = 2, /* Override the primary destination. */
SCTP_ABORT=4, /* Send an ABORT message to the peer. */
SCTP_SACK_IMMEDIATELY = 8, /* SACK should be sent without delay */
SCTP_EOF=MSG_FIN, /* Initiate graceful shutdown process. */
};

View File

@ -263,9 +263,18 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
if (0 == i)
frag |= SCTP_DATA_FIRST_FRAG;
if ((i == (whole - 1)) && !over)
if ((i == (whole - 1)) && !over) {
frag |= SCTP_DATA_LAST_FRAG;
/* The application requests to set the I-bit of the
* last DATA chunk of a user message when providing
* the user message to the SCTP implementation.
*/
if ((sinfo->sinfo_flags & SCTP_EOF) ||
(sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
frag |= SCTP_DATA_SACK_IMM;
}
chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
if (!chunk)
@ -297,6 +306,10 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
else
frag = SCTP_DATA_LAST_FRAG;
if ((sinfo->sinfo_flags & SCTP_EOF) ||
(sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
frag |= SCTP_DATA_SACK_IMM;
chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
if (!chunk)

View File

@ -1011,6 +1011,13 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
break;
case SCTP_XMIT_OK:
/* The sender is in the SHUTDOWN-PENDING state,
* The sender MAY set the I-bit in the DATA
* chunk header.
*/
if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
break;
default: