Vlad Yasevich wrote:
> If the association has a SACK timer pending and now DATA queued
> to be send, we'll try to bundle the SACK with the next application send.
> As such, try encourage bundling by accounting for SACK in the size
> of the first chunk fragment.
>
> Signed-off-by: Vlad Yasevich <vladislav.yasevich@xxxxxx>
> ---
> net/sctp/chunk.c | 9 +++++++++
> 1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
> index 1748ef9..05b532e 100644
> --- a/net/sctp/chunk.c
> +++ b/net/sctp/chunk.c
> @@ -196,6 +196,15 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
> whole = 0;
> first_len = max;
>
> + /* Check to see if we have a pending SACK and try to let it be bundled
> + * with this message. Do this if we don't have any data queued already.
> + * To check that, look at out_qlen and retransmit list.
> + */
> + if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
> + asoc->outqueue.out_qlen == 0 &&
> + list_empty(&asoc->outqueue.retransmit))
> + first_len -= WORD_ROUND(sizeof(sctp_sack_chunk_t));
> +
>
Maybe we should check the first_len < WORD_ROUND(sizeof(sctp_sack_chunk_t)).
Some time when first_len = asoc->frag_point - AUTH_CHUNK - SACK_CHUNK, if
the user set the frag_point to a low value such as 40, the first_len will
be negative value.
The same problem exists when we hold the room for AUTH chunk.
I have checked that asoc->frag_point can be set between 8 and
SCTP_MAX_CHUNK_LEN.
> /* Encourage Cookie-ECHO bundling. */
> if (asoc->state < SCTP_STATE_COOKIE_ECHOED) {
> whole = msg_len / (max - SCTP_ARBITRARY_COOKIE_ECHO_LEN);
>
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