From: Vlad Yasevich <vladislav.yasevich@xxxxxx>
Date: Mon, 7 Jul 2008 17:10:41 -0400
> If we don't have the buffer space or memory allocations fail,
> the data chunk is dropped, but TSN is still reported as received.
> This introduced a data loss that can't be recovered. We should
> only mark TSNs are received after memory allocations finish.
> The one exception is the invalid stream identifier, but that's
> due to user error and is reported back to the user.
>
> This was noticed by Michael Tuexen.
>
> Signed-off-by: Vlad Yasevich <vladislav.yasevich@xxxxxx>
Applied and pushed out to net-2.6, thanks Vlad.
In the future please CC: netdev on changes you actually want me to
commit so other networking developers can look it over.
Thanks!
> ---
> net/sctp/sm_statefuns.c | 9 +++------
> net/sctp/ulpevent.c | 5 +++++
> 2 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
> index 0c9d5a6..fcdb45d 100644
> --- a/net/sctp/sm_statefuns.c
> +++ b/net/sctp/sm_statefuns.c
> @@ -5899,12 +5899,6 @@ static int sctp_eat_data(const struct sctp_association *asoc,
> return SCTP_IERROR_NO_DATA;
> }
>
> - /* If definately accepting the DATA chunk, record its TSN, otherwise
> - * wait for renege processing.
> - */
> - if (SCTP_CMD_CHUNK_ULP == deliver)
> - sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
> -
> chunk->data_accepted = 1;
>
> /* Note: Some chunks may get overcounted (if we drop) or overcounted
> @@ -5924,6 +5918,9 @@ static int sctp_eat_data(const struct sctp_association *asoc,
> * and discard the DATA chunk.
> */
> if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
> + /* Mark tsn as received even though we drop it */
> + sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
> +
> err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
> &data_hdr->stream,
> sizeof(data_hdr->stream));
> diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c
> index ce6cda6..a1f654a 100644
> --- a/net/sctp/ulpevent.c
> +++ b/net/sctp/ulpevent.c
> @@ -710,6 +710,11 @@ struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
> if (!skb)
> goto fail;
>
> + /* Now that all memory allocations for this chunk succeeded, we
> + * can mark it as received so the tsn_map is updated correctly.
> + */
> + sctp_tsnmap_mark(&asoc->peer.tsn_map, ntohl(chunk->subh.data_hdr->tsn));
> +
> /* First calculate the padding, so we don't inadvertently
> * pass up the wrong length to the user.
> *
> --
> 1.5.3.5
>
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