Patchwork [v2] sctp: send abort chunk when max_retrans exceeded

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Submitter Neil Horman
Date Nov. 20, 2012, 8:14 p.m.
Message ID <1353442470-20660-1-git-send-email-nhorman@tuxdriver.com>
Download mbox | patch
Permalink /patch/200502/
State Accepted
Delegated to: David Miller
Headers show

Comments

Neil Horman - Nov. 20, 2012, 8:14 p.m.
In the event that an association exceeds its max_retrans attempts, we should
send an ABORT chunk indicating that we are closing the assocation as a result.
Because of the nature of the error, its unlikely to be received, but its a nice
clean way to close the association if it does make it through, and it will give
anyone watching via tcpdump a clue as to what happened.

Change notes:
v2)
	* Removed erroneous changes from sctp_make_violation_parmlen

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: linux-sctp@vger.kernel.org
---
 include/net/sctp/sm.h    |  2 ++
 net/sctp/sm_make_chunk.c | 19 +++++++++++++++++++
 net/sctp/sm_sideeffect.c |  9 ++++++++-
 3 files changed, 29 insertions(+), 1 deletion(-)
Vlad Yasevich - Nov. 20, 2012, 8:25 p.m.
On 11/20/2012 03:14 PM, Neil Horman wrote:
> In the event that an association exceeds its max_retrans attempts, we should
> send an ABORT chunk indicating that we are closing the assocation as a result.
> Because of the nature of the error, its unlikely to be received, but its a nice
> clean way to close the association if it does make it through, and it will give
> anyone watching via tcpdump a clue as to what happened.
>
> Change notes:
> v2)
> 	* Removed erroneous changes from sctp_make_violation_parmlen
>
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> CC: Vlad Yasevich <vyasevich@gmail.com>

Acked-by: Vlad Yasevich <vyasevich@gmail.com>

-vlad

> CC: "David S. Miller" <davem@davemloft.net>
> CC: linux-sctp@vger.kernel.org
> ---
>   include/net/sctp/sm.h    |  2 ++
>   net/sctp/sm_make_chunk.c | 19 +++++++++++++++++++
>   net/sctp/sm_sideeffect.c |  9 ++++++++-
>   3 files changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
> index b5887e1..2a82d13 100644
> --- a/include/net/sctp/sm.h
> +++ b/include/net/sctp/sm.h
> @@ -234,6 +234,8 @@ struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *,
>   struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *,
>   				   const struct sctp_chunk *,
>   				   struct sctp_paramhdr *);
> +struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *,
> +						   const struct sctp_chunk *);
>   struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *,
>   				  const struct sctp_transport *);
>   struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *,
> diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
> index fbe1636..e0f01a4 100644
> --- a/net/sctp/sm_make_chunk.c
> +++ b/net/sctp/sm_make_chunk.c
> @@ -1090,6 +1090,25 @@ nodata:
>   	return retval;
>   }
>
> +struct sctp_chunk *sctp_make_violation_max_retrans(
> +	const struct sctp_association *asoc,
> +	const struct sctp_chunk *chunk)
> +{
> +	struct sctp_chunk *retval;
> +	static const char error[] = "Association exceeded its max_retans count";
> +	size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
> +
> +	retval = sctp_make_abort(asoc, chunk, payload_len);
> +	if (!retval)
> +		goto nodata;
> +
> +	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
> +	sctp_addto_chunk(retval, sizeof(error), error);
> +
> +nodata:
> +	return retval;
> +}
> +
>   /* Make a HEARTBEAT chunk.  */
>   struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
>   				  const struct sctp_transport *transport)
> diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
> index 6eecf7e..c076956 100644
> --- a/net/sctp/sm_sideeffect.c
> +++ b/net/sctp/sm_sideeffect.c
> @@ -577,7 +577,7 @@ static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
>   				  unsigned int error)
>   {
>   	struct sctp_ulpevent *event;
> -
> +	struct sctp_chunk *abort;
>   	/* Cancel any partial delivery in progress. */
>   	sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
>
> @@ -593,6 +593,13 @@ static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
>   		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
>   				SCTP_ULPEVENT(event));
>
> +	if (asoc->overall_error_count >= asoc->max_retrans) {
> +		abort = sctp_make_violation_max_retrans(asoc, chunk);
> +		if (abort)
> +			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
> +					SCTP_CHUNK(abort));
> +	}
> +
>   	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
>   			SCTP_STATE(SCTP_STATE_CLOSED));
>
>

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David Miller - Nov. 20, 2012, 8:51 p.m.
From: Vlad Yasevich <vyasevich@gmail.com>
Date: Tue, 20 Nov 2012 15:25:56 -0500

> On 11/20/2012 03:14 PM, Neil Horman wrote:
>> In the event that an association exceeds its max_retrans attempts, we
>> should
>> send an ABORT chunk indicating that we are closing the assocation as a
>> result.
>> Because of the nature of the error, its unlikely to be received, but
>> its a nice
>> clean way to close the association if it does make it through, and it
>> will give
>> anyone watching via tcpdump a clue as to what happened.
>>
>> Change notes:
>> v2)
>> 	* Removed erroneous changes from sctp_make_violation_parmlen
>>
>> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
>> CC: Vlad Yasevich <vyasevich@gmail.com>
> 
> Acked-by: Vlad Yasevich <vyasevich@gmail.com>

Applied, thanks.
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Patch

diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index b5887e1..2a82d13 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -234,6 +234,8 @@  struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *,
 struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *,
 				   const struct sctp_chunk *,
 				   struct sctp_paramhdr *);
+struct sctp_chunk *sctp_make_violation_max_retrans(const struct sctp_association *,
+						   const struct sctp_chunk *);
 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *,
 				  const struct sctp_transport *);
 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *,
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index fbe1636..e0f01a4 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1090,6 +1090,25 @@  nodata:
 	return retval;
 }
 
+struct sctp_chunk *sctp_make_violation_max_retrans(
+	const struct sctp_association *asoc,
+	const struct sctp_chunk *chunk)
+{
+	struct sctp_chunk *retval;
+	static const char error[] = "Association exceeded its max_retans count";
+	size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
+
+	retval = sctp_make_abort(asoc, chunk, payload_len);
+	if (!retval)
+		goto nodata;
+
+	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
+	sctp_addto_chunk(retval, sizeof(error), error);
+
+nodata:
+	return retval;
+}
+
 /* Make a HEARTBEAT chunk.  */
 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
 				  const struct sctp_transport *transport)
diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index 6eecf7e..c076956 100644
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -577,7 +577,7 @@  static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 				  unsigned int error)
 {
 	struct sctp_ulpevent *event;
-
+	struct sctp_chunk *abort;
 	/* Cancel any partial delivery in progress. */
 	sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 
@@ -593,6 +593,13 @@  static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 				SCTP_ULPEVENT(event));
 
+	if (asoc->overall_error_count >= asoc->max_retrans) {
+		abort = sctp_make_violation_max_retrans(asoc, chunk);
+		if (abort)
+			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+					SCTP_CHUNK(abort));
+	}
+
 	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 			SCTP_STATE(SCTP_STATE_CLOSED));