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sctp: COOKIE-ACK should back to where the COOKIE-ECHO

PATCH In review Wei Yongjun 2 participants 2 messages Jun 2, 2010 – Jun 14, 2010

Subsystems (2)
Networking SCTP protocol
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Wei Yongjun

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#0 lore raw

PATCH v3 3/3 sctp: COOKIE-ACK should back to where the COOKIE-ECHO

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 <[email protected]>

---
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(-)
net/sctp/output.c +27 -0
index a646681..40f5d76 100644
@@ -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++;
+		}
+	}
+
+	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)
net/sctp/outqueue.c +1 -0
index 782eeeb..2ff4c99 100644
@@ -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;
 		}
net/sctp/sm_make_chunk.c +2 -2
index 459ebff..7d270d6 100644
@@ -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;
 }
Signature · 1 line
1.6.5.2
#1 lore raw
Quoted 45 lines · Wei Yongjun

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 <[email protected]>

---
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(-)
net/sctp/output.c +9 -0
index a646681..40f5d76 100644
@@ -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;

net/sctp/output.c static sctp_xmit_t sctp_packet_bundle_sack(struct sctp_packet *pkt, · line 281

Quoted 10 lines
net/sctp/output.c +10 -0
+		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

Quoted 45 lines
net/sctp/output.c +8 -0
+	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)
net/sctp/outqueue.c +1 -0
index 782eeeb..2ff4c99 100644
@@ -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;
 		}
net/sctp/sm_make_chunk.c +2 -2
index 459ebff..7d270d6 100644
@@ -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;
 }