diff options
| -rw-r--r-- | include/net/sctp/structs.h | 6 | ||||
| -rw-r--r-- | net/sctp/associola.c | 37 |
2 files changed, 41 insertions, 2 deletions
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 97024faaa08..b1bd2689bb7 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -1739,6 +1739,12 @@ struct sctp_association { */ __u32 rwnd_over; + /* Keeps treack of rwnd pressure. This happens when we have + * a window, but not recevie buffer (i.e small packets). This one + * is releases slowly (1 PMTU at a time ). + */ + __u32 rwnd_press; + /* This is the sndbuf size in use for the association. * This corresponds to the sndbuf size for the association, * as specified in the sk->sndbuf. diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 215b56951d7..39c3821b7d3 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -202,6 +202,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a asoc->a_rwnd = asoc->rwnd; asoc->rwnd_over = 0; + asoc->rwnd_press = 0; /* Use my own max window until I learn something better. */ asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW; @@ -1374,6 +1375,17 @@ void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len) asoc->rwnd += len; } + /* If we had window pressure, start recovering it + * once our rwnd had reached the accumulated pressure + * threshold. The idea is to recover slowly, but up + * to the initial advertised window. + */ + if (asoc->rwnd_press && asoc->rwnd >= asoc->rwnd_press) { + int change = min(asoc->pathmtu, asoc->rwnd_press); + asoc->rwnd += change; + asoc->rwnd_press -= change; + } + SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) " "- %u\n", __func__, asoc, len, asoc->rwnd, asoc->rwnd_over, asoc->a_rwnd); @@ -1406,17 +1418,38 @@ void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len) /* Decrease asoc's rwnd by len. */ void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len) { + int rx_count; + int over = 0; + SCTP_ASSERT(asoc->rwnd, "rwnd zero", return); SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return); + + if (asoc->ep->rcvbuf_policy) + rx_count = atomic_read(&asoc->rmem_alloc); + else + rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc); + + /* If we've reached or overflowed our receive buffer, announce + * a 0 rwnd if rwnd would still be positive. Store the + * the pottential pressure overflow so that the window can be restored + * back to original value. + */ + if (rx_count >= asoc->base.sk->sk_rcvbuf) + over = 1; + if (asoc->rwnd >= len) { asoc->rwnd -= len; + if (over) { + asoc->rwnd_press = asoc->rwnd; + asoc->rwnd = 0; + } } else { asoc->rwnd_over = len - asoc->rwnd; asoc->rwnd = 0; } - SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n", + SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u, %u)\n", __func__, asoc, len, asoc->rwnd, - asoc->rwnd_over); + asoc->rwnd_over, asoc->rwnd_press); } /* Build the bind address list for the association based on info from the |