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

[Joe Perches <joe@perches.com>]

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

trivia:

> diff --git a/net/sctp/associola.c b/net/sctp/associola.c

> @@ -871,6 +885,10 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
>  		spc_state = SCTP_ADDR_UNREACHABLE;
>  		break;
>  
> +	case SCTP_TRANSPORT_PF:
> +		transport->state = SCTP_PF;
> +		ulp_notify = false;
> +		break;

nicer to add a newline here

>  	default:
>  		return;
>  	}
> @@ -878,12 +896,15 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
[]
> +	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);