Re: [PATCH v2] sctp: Implement quick failover draft from tsvwg

On Thu, 2012-07-19 at 06:45 -0400, Neil Horman wrote:

On Wed, Jul 18, 2012 at 01:30:58PM -0700, Joe Perches wrote:

quoted

On Wed, 2012-07-18 at 14:01 -0400, Neil Horman wrote:

quoted

I've seen several attempts recently made to do quick failover of sctp transports
by reducing various retransmit timers and counters.  While its possible to
implement a faster failover on multihomed sctp associations, its not
particularly robust, in that it can lead to unneeded retransmits, as well as
false connection failures due to intermittent latency on a network.

[]

quoted

quoted

@@ -878,12 +896,15 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,

[]

quoted

+	if (ulp_notify) {
+		memset(&addr, 0, sizeof(struct sockaddr_storage));
+		memcpy(&addr, &transport->ipaddr,
+		       transport->af_specific->sockaddr_len);

Perhaps it's better to do the memcpy then the memset of the
space left instead.

		memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
		memset((char *)&addr) + transport->af_specific->sockaddr_len, 0,
		       sizeof(struct sockaddr_storage) - transport->af_specific->sockaddr_len);

hmm, not sure about that. It works either way for me, but I've not changed that
code, just the condition under which it was executed.  I'd rather save cleanups
like that for a separate patch if you don't mind.

Not a bit.

It's almost certain reversing the order is slower for v4
addresses anyway.  It might be slower for v6 too given
the arithmetic.

cheers, Joe