Wei Yongjun wrote:
> This patch fixed to send COOKIE-ACK back to where the COOKIE-ECHO
> came from, and if COOKIE ACK is sent to an UNCONFIRMED address,
> bundled it with a HEARTBEAT including a nonce. Based on RFC4960:
>
> Section 6.4. Multi-Homed SCTP Endpoints
>
> An endpoint SHOULD transmit reply chunks (e.g., SACK, HEARTBEAT ACK,
> etc.) to the same destination transport address from which it
> received the DATA or control chunk to which it is replying.
>
> Section 5.4. Path Verification:
>
> - A COOKIE ACK MAY be sent to an UNCONFIRMED address, but it MUST be
> bundled with a HEARTBEAT including a nonce. An implementation
> that does NOT support bundling MUST NOT send a COOKIE ACK to an
> UNCONFIRMED address.
>
> Signed-off-by: Wei Yongjun <yjwei@xxxxxxxxxxxxxx>
> ---
> v2 -> V3
> - bundle HB at the first
> - update error counters, and set hb_sent to update timer when expires
> ---
> net/sctp/output.c | 27 +++++++++++++++++++++++++++
> net/sctp/outqueue.c | 1 +
> net/sctp/sm_make_chunk.c | 4 ++--
> 3 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/net/sctp/output.c b/net/sctp/output.c
> index a646681..40f5d76 100644
> --- a/net/sctp/output.c
> +++ b/net/sctp/output.c
> @@ -260,6 +260,28 @@ static sctp_xmit_t sctp_packet_bundle_sack(struct sctp_packet *pkt,
> return retval;
> }
>
> +/* Try to bundle a HEARTBEAT with the packet. */
> +static sctp_xmit_t sctp_packet_bundle_hb(struct sctp_packet *pkt,
> + struct sctp_chunk *chunk)
> +{
> + sctp_xmit_t retval = SCTP_XMIT_OK;
> +
> + if (pkt->transport->state == SCTP_UNCONFIRMED &&
> + chunk->chunk_hdr->type == SCTP_CID_COOKIE_ACK) {
> + struct sctp_transport *transport = pkt->transport;
> + struct sctp_chunk *hb;
> +
> + hb = sctp_make_heartbeat(transport->asoc, transport);
> + if (hb) {
> + retval = sctp_packet_append_chunk(pkt, hb);
> + transport->hb_sent = 1;
> + transport->error_count++;
> + }
> + }
> +
You need to check that HB are enabled on the transport. If the HB are disabled,
we can't send the cookie-ack.
-vlad
> + return retval;
> +}
> +
> /* Append a chunk to the offered packet reporting back any inability to do
> * so.
> */
> @@ -292,6 +314,11 @@ sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
> if (retval != SCTP_XMIT_OK)
> goto finish;
>
> + /* Try to bundle HEARTBEAT chunk */
> + retval = sctp_packet_bundle_hb(packet, chunk);
> + if (retval != SCTP_XMIT_OK)
> + goto finish;
> +
> /* Check to see if this chunk will fit into the packet */
> retval = sctp_packet_will_fit(packet, chunk, chunk_len);
> if (retval != SCTP_XMIT_OK)
> diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
> index 782eeeb..2ff4c99 100644
> --- a/net/sctp/outqueue.c
> +++ b/net/sctp/outqueue.c
> @@ -800,6 +800,7 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
> */
> if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
> chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
> + chunk->chunk_hdr->type != SCTP_CID_COOKIE_ACK &&
> chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
> new_transport = asoc->peer.active_path;
> }
> diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
> index 459ebff..7d270d6 100644
> --- a/net/sctp/sm_make_chunk.c
> +++ b/net/sctp/sm_make_chunk.c
> @@ -602,8 +602,8 @@ struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
> *
> * [COOKIE ACK back to where the COOKIE ECHO came from.]
> */
> - if (retval && chunk)
> - retval->transport = chunk->transport;
> + if (retval)
> + retval->dest = chunk->source;
>
> return retval;
> }
--
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