Re: [V2 PATCH 1/1] net: sctp: dynamically enable or disable pf state

[Vlad Yasevich <vyasevich@gmail.com>]

On 12/14/2015 01:22 AM, zyjzyj2000@gmail.com wrote:
> From: Zhu Yanjun <zyjzyj2000@gmail.com>
> 
> As we all know, the value of pf_retrans >= max_retrans_path can
> disable pf state. The variables of pf_retrans and max_retrans_path
> can be changed by the user space application.
> 
> Sometimes the user expects to disable pf state while the 2
> variables are changed to enable pf state. So it is necessary to
> introduce a new variable to disable pf state.
> 
> According to the suggestions from Vlad Yasevich, extra1 and extra2
> are removed. The initialization of pf_enable is added.
> 
> Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com>

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

-vlad

> ---
>  include/net/netns/sctp.h |    7 +++++++
>  net/sctp/protocol.c      |    3 +++
>  net/sctp/sm_sideeffect.c |    5 ++++-
>  net/sctp/sysctl.c        |    7 +++++++
>  4 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/include/net/netns/sctp.h b/include/net/netns/sctp.h
> index 8ba379f..c501d67 100644
> --- a/include/net/netns/sctp.h
> +++ b/include/net/netns/sctp.h
> @@ -89,6 +89,13 @@ struct netns_sctp {
>  	int pf_retrans;
>  
>  	/*
> +	 * Disable Potentially-Failed feature, the feature is enabled by default
> +	 * pf_enable	-  0  : disable pf
> +	 *		- >0  : enable pf
> +	 */
> +	int pf_enable;
> +
> +	/*
>  	 * Policy for preforming sctp/socket accounting
>  	 * 0   - do socket level accounting, all assocs share sk_sndbuf
>  	 * 1   - do sctp accounting, each asoc may use sk_sndbuf bytes
> diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
> index 4d9912f..571a631 100644
> --- a/net/sctp/protocol.c
> +++ b/net/sctp/protocol.c
> @@ -1223,6 +1223,9 @@ static int __net_init sctp_defaults_init(struct net *net)
>  	/* Max.Burst		    - 4 */
>  	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;
>  
> +	/* Enable pf state by default */
> +	net->sctp.pf_enable = 1;
> +
>  	/* Association.Max.Retrans  - 10 attempts
>  	 * Path.Max.Retrans         - 5  attempts (per destination address)
>  	 * Max.Init.Retransmits     - 8  attempts
> diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
> index 6098d4c..05cd164 100644
> --- a/net/sctp/sm_sideeffect.c
> +++ b/net/sctp/sm_sideeffect.c
> @@ -477,6 +477,8 @@ static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
>  					 struct sctp_transport *transport,
>  					 int is_hb)
>  {
> +	struct net *net = sock_net(asoc->base.sk);
> +
>  	/* The check for association's overall error counter exceeding the
>  	 * threshold is done in the state function.
>  	 */
> @@ -503,7 +505,8 @@ static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
>  	 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
>  	 * see SCTP Quick Failover Draft, section 5.1
>  	 */
> -	if ((transport->state == SCTP_ACTIVE) &&
> +	if (net->sctp.pf_enable &&
> +	   (transport->state == SCTP_ACTIVE) &&
>  	   (asoc->pf_retrans < transport->pathmaxrxt) &&
>  	   (transport->error_count > asoc->pf_retrans)) {
>  
> diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
> index 26d50c5..ccbfc93 100644
> --- a/net/sctp/sysctl.c
> +++ b/net/sctp/sysctl.c
> @@ -308,6 +308,13 @@ static struct ctl_table sctp_net_table[] = {
>  		.extra1		= &max_autoclose_min,
>  		.extra2		= &max_autoclose_max,
>  	},
> +	{
> +		.procname	= "pf_enable",
> +		.data		= &init_net.sctp.pf_enable,
> +		.maxlen		= sizeof(int),
> +		.mode		= 0644,
> +		.proc_handler	= proc_dointvec,
> +	},
>  
>  	{ /* sentinel */ }
>  };
>