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sctp: fast recovery algorithm is per association.

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SCTP fast recovery algorithm really applies per association
and impacts all transports.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
This commit is contained in:
Vlad Yasevich 2010-04-30 22:41:10 -04:00
parent b2cf9b6bd9
commit cf9b4812e1
2 changed files with 23 additions and 21 deletions
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12
include/net/sctp/structs.h
View file

@ -895,9 +895,6 @@ struct sctp_transport {
*/
hb_sent:1,
/* Flag to track the current fast recovery state */
fast_recovery:1,
/* Is the Path MTU update pending on this tranport */
pmtu_pending:1,
@ -952,9 +949,6 @@ struct sctp_transport {
__u32 burst_limited; /* Holds old cwnd when max.burst is applied */
/* TSN marking the fast recovery exit point */
__u32 fast_recovery_exit;
/* Destination */
struct dst_entry *dst;
/* Source address. */
@ -1723,6 +1717,12 @@ struct sctp_association {
/* Highest TSN that is acknowledged by incoming SACKs. */
__u32 highest_sacked;
/* TSN marking the fast recovery exit point */
__u32 fast_recovery_exit;
/* Flag to track the current fast recovery state */
__u8 fast_recovery;
/* The number of unacknowledged data chunks. Reported through
* the SCTP_STATUS sockopt.
*/

32
net/sctp/transport.c
View file

@ -378,15 +378,16 @@ void sctp_transport_update_rto(struct sctp_transport *tp, __u32 rtt)
void sctp_transport_raise_cwnd(struct sctp_transport *transport,
__u32 sack_ctsn, __u32 bytes_acked)
{
struct sctp_association *asoc = transport->asoc;
__u32 cwnd, ssthresh, flight_size, pba, pmtu;
cwnd = transport->cwnd;
flight_size = transport->flight_size;
/* See if we need to exit Fast Recovery first */
if (transport->fast_recovery &&
TSN_lte(transport->fast_recovery_exit, sack_ctsn))
transport->fast_recovery = 0;
if (asoc->fast_recovery &&
TSN_lte(asoc->fast_recovery_exit, sack_ctsn))
asoc->fast_recovery = 0;
/* The appropriate cwnd increase algorithm is performed if, and only
* if the cumulative TSN whould advanced and the congestion window is
@ -415,7 +416,7 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport,
* 2) the destination's path MTU. This upper bound protects
* against the ACK-Splitting attack outlined in [SAVAGE99].
*/
if (transport->fast_recovery)
if (asoc->fast_recovery)
return;
if (bytes_acked > pmtu)
@ -466,6 +467,8 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport,
void sctp_transport_lower_cwnd(struct sctp_transport *transport,
sctp_lower_cwnd_t reason)
{
struct sctp_association *asoc = transport->asoc;
switch (reason) {
case SCTP_LOWER_CWND_T3_RTX:
/* RFC 2960 Section 7.2.3, sctpimpguide
@ -476,11 +479,11 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
* partial_bytes_acked = 0
*/
transport->ssthresh = max(transport->cwnd/2,
4*transport->asoc->pathmtu);
transport->cwnd = transport->asoc->pathmtu;
4*asoc->pathmtu);
transport->cwnd = asoc->pathmtu;
/* T3-rtx also clears fast recovery on the transport */
transport->fast_recovery = 0;
/* T3-rtx also clears fast recovery */
asoc->fast_recovery = 0;
break;
case SCTP_LOWER_CWND_FAST_RTX:
@ -496,15 +499,15 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
* cwnd = ssthresh
* partial_bytes_acked = 0
*/
if (transport->fast_recovery)
if (asoc->fast_recovery)
return;
/* Mark Fast recovery */
transport->fast_recovery = 1;
transport->fast_recovery_exit = transport->asoc->next_tsn - 1;
asoc->fast_recovery = 1;
asoc->fast_recovery_exit = asoc->next_tsn - 1;
transport->ssthresh = max(transport->cwnd/2,
4*transport->asoc->pathmtu);
4*asoc->pathmtu);
transport->cwnd = transport->ssthresh;
break;
@ -524,7 +527,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
if (time_after(jiffies, transport->last_time_ecne_reduced +
transport->rtt)) {
transport->ssthresh = max(transport->cwnd/2,
4*transport->asoc->pathmtu);
4*asoc->pathmtu);
transport->cwnd = transport->ssthresh;
transport->last_time_ecne_reduced = jiffies;
}
@ -540,7 +543,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
* interval.
*/
transport->cwnd = max(transport->cwnd/2,
4*transport->asoc->pathmtu);
4*asoc->pathmtu);
break;
}
@ -625,7 +628,6 @@ void sctp_transport_reset(struct sctp_transport *t)
t->error_count = 0;
t->rto_pending = 0;
t->hb_sent = 0;
t->fast_recovery = 0;
/* Initialize the state information for SFR-CACC */
t->cacc.changeover_active = 0;