From b93d6471748de2ce02cc24774b774deb306a57a8 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Mon, 23 Nov 2009 15:53:56 -0500 Subject: [PATCH] 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 Signed-off-by: Vlad Yasevich --- include/net/sctp/user.h | 1 + net/sctp/chunk.c | 15 ++++++++++++++- net/sctp/outqueue.c | 7 +++++++ 3 files changed, 22 insertions(+), 1 deletion(-) diff --git a/include/net/sctp/user.h b/include/net/sctp/user.h index be2334aaf52e..50b2431405f2 100644 --- a/include/net/sctp/user.h +++ b/include/net/sctp/user.h @@ -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. */ }; diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c index acf7c4d128f7..8e4320040f05 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c @@ -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) diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index c9f20e28521b..5732661c87d3 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -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: -- 2.39.2