Subject: Re: [PATCH v5] sctp: Implement quick failover draft from tsvwg

From: Flavio Leitner <[email-masked]>
Date: Fri, 20 Jul 2012 16:10:01 -0300

On Fri, 20 Jul 2012 14:51:59 -0400
Neil Horman <[email-masked]> 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.
> 
> Instead, lets implement the new ietf quick failover draft found here:
> http://tools.ietf.org/html/draft-nishida-tsvwg-sctp-failover-05
> 
> This will let the sctp stack identify transports that have had a small number of
> errors, and avoid using them quickly until their reliability can be
> re-established.  I've tested this out on two virt guests connected via multiple
> isolated virt networks and believe its in compliance with the above draft and
> works well.
> 
> Signed-off-by: Neil Horman <[email-masked]>
> CC: Vlad Yasevich <[email-masked]>
> CC: Sridhar Samudrala <[email-masked]>
> CC: "David S. Miller" <[email-masked]>
> CC: [email-masked]
> CC: [email-masked]
> 
> ---
> Change notes:
> 
> V2)
> - Added socket option API from section 6.1 of the specification, as per
> request from Vlad. Adding this socket option allows us to alter both the path
> maximum retransmit value and the path partial failure threshold for each
> transport and the association as a whole.
> 
> - Added a per transport pf_retrans value, and initialized it from the
> association value.  This makes each transport independently configurable as per
> the socket option above, and prevents changes in the sysctl from bleeding into
> an already created association.
> 
> V3)
> - Cleaned up some line spacing (Joe Perches)
> - Fixed some socket option user data sanitization (Vlad Yasevich)
> 
> V4)
> - Added additional documentation (Flavio Leitner)
> 
> V5)
> - Modified setsockopt option to ignore 0 pathmaxrxt rather than return
>   error (Vlad Yasevich)
> - Modified getsocopt to return option length written (Vlad Y.)
> ---
>  Documentation/networking/ip-sysctl.txt |   14 +++++
>  include/net/sctp/constants.h           |    1 +
>  include/net/sctp/structs.h             |   20 ++++++-
>  include/net/sctp/user.h                |   11 ++++
>  net/sctp/associola.c                   |   37 ++++++++++--
>  net/sctp/outqueue.c                    |    6 +-
>  net/sctp/sm_sideeffect.c               |   33 +++++++++-
>  net/sctp/socket.c                      |  100 ++++++++++++++++++++++++++++++++
>  net/sctp/sysctl.c                      |    9 +++
>  net/sctp/transport.c                   |    4 +-
>  10 files changed, 220 insertions(+), 15 deletions(-)
> 
> diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
> index 47b6c79..c636f9c 100644
> --- a/Documentation/networking/ip-sysctl.txt
> +++ b/Documentation/networking/ip-sysctl.txt
> @@ -1408,6 +1408,20 @@ path_max_retrans - INTEGER
>  
>  	Default: 5
>  
> +pf_retrans - INTEGER
> +	The number of retransmissions that will be attempted on a given path
> +	before traffic is redirected to an alternate transport (should one
> +	exist).  Note this is distinct from path_max_retrans, as a path that
> +	passes the pf_retrans threshold can still be used.  Its only
> +	deprioritized when a transmission path is selected by the stack.  This
> +	setting is primarily used to enable fast failover mechanisms without
> +	having to reduce path_max_retrans to a very low value.  See:
> +	http://www.ietf.org/id/draft-nishida-tsvwg-sctp-failover-05.txt
> +	for details.  Note also that a value of pf_retrans > path_max_retrans
> +	disables this feature
> +
> +	Default: 0
> +
>  rto_initial - INTEGER
>  	The initial round trip timeout value in milliseconds that will be used
>  	in calculating round trip times.  This is the initial time interval
> diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
> index 942b864..d053d2e 100644
> --- a/include/net/sctp/constants.h
> +++ b/include/net/sctp/constants.h
> @@ -334,6 +334,7 @@ typedef enum {
>  typedef enum {
>  	SCTP_TRANSPORT_UP,
>  	SCTP_TRANSPORT_DOWN,
> +	SCTP_TRANSPORT_PF,
>  } sctp_transport_cmd_t;
>  
>  /* These are the address scopes defined mainly for IPv4 addresses
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index e4652fe..cee0678 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -161,6 +161,12 @@ extern struct sctp_globals {
>  	int max_retrans_path;
>  	int max_retrans_init;
>  
> +	/* Potentially-Failed.Max.Retrans sysctl value
> +	 * taken from:
> +	 * http://tools.ietf.org/html/draft-nishida-tsvwg-sctp-failover-05
> +	 */
> +	int pf_retrans;
> +
>  	/*
>  	 * Policy for preforming sctp/socket accounting
>  	 * 0   - do socket level accounting, all assocs share sk_sndbuf
> @@ -258,6 +264,7 @@ extern struct sctp_globals {
>  #define sctp_sndbuf_policy	 	(sctp_globals.sndbuf_policy)
>  #define sctp_rcvbuf_policy	 	(sctp_globals.rcvbuf_policy)
>  #define sctp_max_retrans_path		(sctp_globals.max_retrans_path)
> +#define sctp_pf_retrans			(sctp_globals.pf_retrans)
>  #define sctp_max_retrans_init		(sctp_globals.max_retrans_init)
>  #define sctp_sack_timeout		(sctp_globals.sack_timeout)
>  #define sctp_hb_interval		(sctp_globals.hb_interval)
> @@ -987,10 +994,15 @@ struct sctp_transport {
>  
>  	/* This is the max_retrans value for the transport and will
>  	 * be initialized from the assocs value.  This can be changed
> -	 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
> +	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
>  	 */
>  	__u16 pathmaxrxt;
>  
> +	/* This is the partially failed retrans value for the transport
> +	 * and will be initialized from the assocs value.  This can be changed
> +	 * using the SCTP_PEER_ADDR_THLDS socket option
> +	 */
> +	int pf_retrans;
>  	/* PMTU	      : The current known path MTU.  */
>  	__u32 pathmtu;
>  
> @@ -1660,6 +1672,12 @@ struct sctp_association {
>  	 */
>  	int max_retrans;
>  
> +	/* This is the partially failed retrans value for the transport
> +	 * and will be initialized from the assocs value.  This can be
> +	 * changed using the SCTP_PEER_ADDR_THLDS socket option
> +	 */
> +	int pf_retrans;
> +
>  	/* Maximum number of times the endpoint will retransmit INIT  */
>  	__u16 max_init_attempts;
>  
> diff --git a/include/net/sctp/user.h b/include/net/sctp/user.h
> index 0842ef0..1b02d7a 100644
> --- a/include/net/sctp/user.h
> +++ b/include/net/sctp/user.h
> @@ -93,6 +93,7 @@ typedef __s32 sctp_assoc_t;
>  #define SCTP_GET_ASSOC_NUMBER	28	/* Read only */
>  #define SCTP_GET_ASSOC_ID_LIST	29	/* Read only */
>  #define SCTP_AUTO_ASCONF       30
> +#define SCTP_PEER_ADDR_THLDS	31
>  
>  /* Internal Socket Options. Some of the sctp library functions are
>   * implemented using these socket options.
> @@ -649,6 +650,7 @@ struct sctp_paddrinfo {
>   */
>  enum sctp_spinfo_state {
>  	SCTP_INACTIVE,
> +	SCTP_PF,
>  	SCTP_ACTIVE,
>  	SCTP_UNCONFIRMED,
>  	SCTP_UNKNOWN = 0xffff  /* Value used for transport state unknown */
> @@ -741,4 +743,13 @@ typedef struct {
>  	int sd;
>  } sctp_peeloff_arg_t;
>  
> +/*
> + *  Peer Address Thresholds socket option
> + */
> +struct sctp_paddrthlds {
> +	sctp_assoc_t spt_assoc_id;
> +	struct sockaddr_storage spt_address;
> +	__u16 spt_pathmaxrxt;
> +	__u16 spt_pathpfthld;
> +};
>  #endif /* __net_sctp_user_h__ */
> diff --git a/net/sctp/associola.c b/net/sctp/associola.c
> index 5bc9ab1..90fe36b 100644
> --- a/net/sctp/associola.c
> +++ b/net/sctp/associola.c
> @@ -124,6 +124,8 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
>  	 * socket values.
>  	 */
>  	asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
> +	asoc->pf_retrans  = sctp_pf_retrans;
> +
>  	asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
>  	asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
>  	asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
> @@ -685,6 +687,9 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
>  	/* Set the path max_retrans.  */
>  	peer->pathmaxrxt = asoc->pathmaxrxt;
>  
> +	/* And the partial failure retrnas threshold */
> +	peer->pf_retrans = asoc->pf_retrans;
> +
>  	/* Initialize the peer's SACK delay timeout based on the
>  	 * association configured value.
>  	 */
> @@ -840,6 +845,7 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
>  	struct sctp_ulpevent *event;
>  	struct sockaddr_storage addr;
>  	int spc_state = 0;
> +	bool ulp_notify = true;
>  
>  	/* Record the transition on the transport.  */
>  	switch (command) {
> @@ -853,6 +859,14 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
>  			spc_state = SCTP_ADDR_CONFIRMED;
>  		else
>  			spc_state = SCTP_ADDR_AVAILABLE;
> +		/* Don't inform ULP about transition from PF to
> +		 * active state and set cwnd to 1, see SCTP
> +		 * Quick failover draft section 5.1, point 5
> +		 */
> +		if (transport->state == SCTP_PF) {
> +			ulp_notify = false;
> +			transport->cwnd = 1;
> +		}
>  		transport->state = SCTP_ACTIVE;
>  		break;
>  
> @@ -871,6 +885,11 @@ 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;
> +
>  	default:
>  		return;
>  	}
> @@ -878,12 +897,15 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
>  	/* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
>  	 * user.
>  	 */
> -	memset(&addr, 0, sizeof(struct sockaddr_storage));
> -	memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
> -	event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
> -				0, spc_state, error, GFP_ATOMIC);
> -	if (event)
> -		sctp_ulpq_tail_event(&asoc->ulpq, event);
> +	if (ulp_notify) {
> +		memset(&addr, 0, sizeof(struct sockaddr_storage));
> +		memcpy(&addr, &transport->ipaddr,
> +		       transport->af_specific->sockaddr_len);
> +		event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
> +					0, spc_state, error, GFP_ATOMIC);
> +		if (event)
> +			sctp_ulpq_tail_event(&asoc->ulpq, event);
> +	}
>  
>  	/* Select new active and retran paths. */
>  
> @@ -899,7 +921,8 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
>  			transports) {
>  
>  		if ((t->state == SCTP_INACTIVE) ||
> -		    (t->state == SCTP_UNCONFIRMED))
> +		    (t->state == SCTP_UNCONFIRMED) ||
> +		    (t->state == SCTP_PF))
>  			continue;
>  		if (!first || t->last_time_heard > first->last_time_heard) {
>  			second = first;
> diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
> index a0fa19f..e7aa177c 100644
> --- a/net/sctp/outqueue.c
> +++ b/net/sctp/outqueue.c
> @@ -792,7 +792,8 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
>  			if (!new_transport)
>  				new_transport = asoc->peer.active_path;
>  		} else if ((new_transport->state == SCTP_INACTIVE) ||
> -			   (new_transport->state == SCTP_UNCONFIRMED)) {
> +			   (new_transport->state == SCTP_UNCONFIRMED) ||
> +			   (new_transport->state == SCTP_PF)) {
>  			/* If the chunk is Heartbeat or Heartbeat Ack,
>  			 * send it to chunk->transport, even if it's
>  			 * inactive.
> @@ -987,7 +988,8 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
>  			new_transport = chunk->transport;
>  			if (!new_transport ||
>  			    ((new_transport->state == SCTP_INACTIVE) ||
> -			     (new_transport->state == SCTP_UNCONFIRMED)))
> +			     (new_transport->state == SCTP_UNCONFIRMED) ||
> +			     (new_transport->state == SCTP_PF)))
>  				new_transport = asoc->peer.active_path;
>  			if (new_transport->state == SCTP_UNCONFIRMED)
>  				continue;
> diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
> index c96d1a8..285e26a 100644
> --- a/net/sctp/sm_sideeffect.c
> +++ b/net/sctp/sm_sideeffect.c
> @@ -76,6 +76,8 @@ static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
>  			     sctp_cmd_seq_t *commands,
>  			     gfp_t gfp);
>  
> +static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
> +				     struct sctp_transport *t);
>  /********************************************************************
>   * Helper functions
>   ********************************************************************/
> @@ -470,7 +472,8 @@ sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
>   * notification SHOULD be sent to the upper layer.
>   *
>   */
> -static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
> +static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
> +					 struct sctp_association *asoc,
>  					 struct sctp_transport *transport,
>  					 int is_hb)
>  {
> @@ -495,6 +498,23 @@ static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
>  			transport->error_count++;
>  	}
>  
> +	/* If the transport error count is greater than the pf_retrans
> +	 * threshold, and less than pathmaxrtx, then mark this transport
> +	 * as Partially Failed, ee SCTP Quick Failover Draft, secon 5.1,
> +	 * point 1
> +	 */
> +	if ((transport->state != SCTP_PF) &&
> +	   (asoc->pf_retrans < transport->pathmaxrxt) &&
> +	   (transport->error_count > asoc->pf_retrans)) {
> +
> +		sctp_assoc_control_transport(asoc, transport,
> +					     SCTP_TRANSPORT_PF,
> +					     0);
> +
> +		/* Update the hb timer to resend a heartbeat every rto */
> +		sctp_cmd_hb_timer_update(commands, transport);
> +	}
> +
>  	if (transport->state != SCTP_INACTIVE &&
>  	    (transport->error_count > transport->pathmaxrxt)) {
>  		SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
> @@ -699,6 +719,10 @@ static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
>  					     SCTP_HEARTBEAT_SUCCESS);
>  	}
>  
> +	if (t->state == SCTP_PF)
> +		sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
> +					     SCTP_HEARTBEAT_SUCCESS);
> +
>  	/* The receiver of the HEARTBEAT ACK should also perform an
>  	 * RTT measurement for that destination transport address
>  	 * using the time value carried in the HEARTBEAT ACK chunk.
> @@ -1565,8 +1589,8 @@ static int sctp_cmd_interpreter(sctp_event_t event_type,
>  
>  		case SCTP_CMD_STRIKE:
>  			/* Mark one strike against a transport.  */
> -			sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
> -						    0);
> +			sctp_do_8_2_transport_strike(commands, asoc,
> +						    cmd->obj.transport, 0);
>  			break;
>  
>  		case SCTP_CMD_TRANSPORT_IDLE:
> @@ -1576,7 +1600,8 @@ static int sctp_cmd_interpreter(sctp_event_t event_type,
>  
>  		case SCTP_CMD_TRANSPORT_HB_SENT:
>  			t = cmd->obj.transport;
> -			sctp_do_8_2_transport_strike(asoc, t, 1);
> +			sctp_do_8_2_transport_strike(commands, asoc,
> +						     t, 1);
>  			t->hb_sent = 1;
>  			break;
>  
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index b3b8a8d..bba551f 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -3470,6 +3470,56 @@ static int sctp_setsockopt_auto_asconf(struct sock *sk, char __user *optval,
>  }
>  
>  
> +/*
> + * SCTP_PEER_ADDR_THLDS
> + *
> + * This option allows us to alter the partially failed threshold for one or all
> + * transports in an association.  See Section 6.1 of:
> + * http://www.ietf.org/id/draft-nishida-tsvwg-sctp-failover-05.txt
> + */
> +static int sctp_setsockopt_paddr_thresholds(struct sock *sk,
> +					    char __user *optval,
> +					    unsigned int optlen)
> +{
> +	struct sctp_paddrthlds val;
> +	struct sctp_transport *trans;
> +	struct sctp_association *asoc;
> +
> +	if (optlen < sizeof(struct sctp_paddrthlds))
> +		return -EINVAL;
> +	if (copy_from_user(&val, (struct sctp_paddrthlds __user *)optval,
> +			   sizeof(struct sctp_paddrthlds)))
> +		return -EFAULT;
> +
> +
> +	if (sctp_is_any(sk, (const union sctp_addr *)&val.spt_address)) {
> +		asoc = sctp_id2assoc(sk, val.spt_assoc_id);
> +		if (!asoc)
> +			return -ENOENT;
> +		list_for_each_entry(trans, &asoc->peer.transport_addr_list,
> +				    transports) {
> +			if (val.spt_pathmaxrxt)
> +				trans->pathmaxrxt = val.spt_pathmaxrxt;
> +			trans->pf_retrans = val.spt_pathpfthld;
> +		}
> +
> +		if (val.spt_pathmaxrxt)
> +			asoc->pathmaxrxt = val.spt_pathmaxrxt;
> +		asoc->pf_retrans = val.spt_pathpfthld;
> +	} else {
> +		trans = sctp_addr_id2transport(sk, &val.spt_address,
> +					       val.spt_assoc_id);
> +		if (!trans)
> +			return -ENOENT;
> +
> +		if (val.spt_pathmaxrxt)
> +			trans->pathmaxrxt = val.spt_pathmaxrxt;
> +		trans->pf_retrans = val.spt_pathpfthld;
> +	}
> +
> +	return 0;
> +}
> +
>  /* API 6.2 setsockopt(), getsockopt()
>   *
>   * Applications use setsockopt() and getsockopt() to set or retrieve
> @@ -3619,6 +3669,9 @@ SCTP_STATIC int sctp_setsockopt(struct sock *sk, int level, int optname,
>  	case SCTP_AUTO_ASCONF:
>  		retval = sctp_setsockopt_auto_asconf(sk, optval, optlen);
>  		break;
> +	case SCTP_PEER_ADDR_THLDS:
> +		retval = sctp_setsockopt_paddr_thresholds(sk, optval, optlen);
> +		break;
>  	default:
>  		retval = -ENOPROTOOPT;
>  		break;
> @@ -5490,6 +5543,50 @@ static int sctp_getsockopt_assoc_ids(struct sock *sk, int len,
>  	return 0;
>  }
>  
> +/*
> + * SCTP_PEER_ADDR_THLDS
> + *
> + * This option allows us to fetch the partially failed threshold for one or all
> + * transports in an association.  See Section 6.1 of:
> + * http://www.ietf.org/id/draft-nishida-tsvwg-sctp-failover-05.txt
> + */
> +static int sctp_getsockopt_paddr_thresholds(struct sock *sk,
> +					    char __user *optval,
> +					    int optlen)
> +{
> +	struct sctp_paddrthlds val;
> +	struct sctp_transport *trans;
> +	struct sctp_association *asoc;
> +
> +	if (optlen < sizeof(struct sctp_paddrthlds))
> +		return -EINVAL;
> +	optlen = sizeof(struct sctp_paddrthlds);
> +	if (copy_from_user(&val, (struct sctp_paddrthlds __user *)optval, optlen))
> +		return -EFAULT;
> +
> +	if (sctp_is_any(sk, (const union sctp_addr *)&val.spt_address)) {
> +		asoc = sctp_id2assoc(sk, val.spt_assoc_id);
> +		if (!asoc)
> +			return -ENOENT;
> +
> +		val.spt_pathpfthld = asoc->pf_retrans;
> +		val.spt_pathmaxrxt = asoc->pathmaxrxt;
> +	} else {
> +		trans = sctp_addr_id2transport(sk, &val.spt_address,
> +					       val.spt_assoc_id);
> +		if (!trans)
> +			return -ENOENT;
> +
> +		val.spt_pathmaxrxt = trans->pathmaxrxt;
> +		val.spt_pathpfthld = trans->pf_retrans;
> +	}
> +
> +	if (copy_to_user(optval, &val, optlen))
> +		return -EFAULT;
> +
> +	return optlen;
> +}
> +
>  SCTP_STATIC int sctp_getsockopt(struct sock *sk, int level, int optname,
>  				char __user *optval, int __user *optlen)
>  {
> @@ -5628,6 +5725,9 @@ SCTP_STATIC int sctp_getsockopt(struct sock *sk, int level, int optname,
>  	case SCTP_AUTO_ASCONF:
>  		retval = sctp_getsockopt_auto_asconf(sk, len, optval, optlen);
>  		break;
> +	case SCTP_PEER_ADDR_THLDS:
> +		retval = sctp_getsockopt_paddr_thresholds(sk, optval, len);
> +		break;
>  	default:
>  		retval = -ENOPROTOOPT;
>  		break;
> diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
> index e5fe639..2b2bfe9 100644
> --- a/net/sctp/sysctl.c
> +++ b/net/sctp/sysctl.c
> @@ -141,6 +141,15 @@ static ctl_table sctp_table[] = {
>  		.extra2		= &int_max
>  	},
>  	{
> +		.procname	= "pf_retrans",
> +		.data		= &sctp_pf_retrans,
> +		.maxlen		= sizeof(int),
> +		.mode		= 0644,
> +		.proc_handler	= proc_dointvec_minmax,
> +		.extra1		= &zero,
> +		.extra2		= &int_max
> +	},
> +	{
>  		.procname	= "max_init_retransmits",
>  		.data		= &sctp_max_retrans_init,
>  		.maxlen		= sizeof(int),
> diff --git a/net/sctp/transport.c b/net/sctp/transport.c
> index b026ba0..194d0f3 100644
> --- a/net/sctp/transport.c
> +++ b/net/sctp/transport.c
> @@ -85,6 +85,7 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
>  
>  	/* Initialize the default path max_retrans.  */
>  	peer->pathmaxrxt  = sctp_max_retrans_path;
> +	peer->pf_retrans  = sctp_pf_retrans;
>  
>  	INIT_LIST_HEAD(&peer->transmitted);
>  	INIT_LIST_HEAD(&peer->send_ready);
> @@ -585,7 +586,8 @@ unsigned long sctp_transport_timeout(struct sctp_transport *t)
>  {
>  	unsigned long timeout;
>  	timeout = t->rto + sctp_jitter(t->rto);
> -	if (t->state != SCTP_UNCONFIRMED)
> +	if ((t->state != SCTP_UNCONFIRMED) &&
> +	    (t->state != SCTP_PF))
>  		timeout += t->hbinterval;
>  	timeout += jiffies;
>  	return timeout;

Reviewed-by: Flavio Leitner <[email-masked]>

fbl