From 92548ec2f1f92d0c0b60ce59592b645571672568 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Tue, 22 Jun 2021 14:04:51 -0400 Subject: sctp: add the probe timer in transport for PLPMTUD There are 3 timers described in rfc8899#section-5.1.1: PROBE_TIMER, PMTU_RAISE_TIMER, CONFIRMATION_TIMER This patches adds a 'probe_timer' in transport, and it works as either PROBE_TIMER or PMTU_RAISE_TIMER. At most time, it works as PROBE_TIMER and expires every a 'probe_interval' time to send the HB probe packet. When transport pl enters COMPLETE state, it works as PMTU_RAISE_TIMER and expires in 'probe_interval * 30' time to go back to SEARCH state and do searching again. SCTP HB is an acknowledged packet, CONFIRMATION_TIMER is not needed. The timer will start when transport pl enters BASE state and stop when it enters DISABLED state. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/sm_sideeffect.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'net/sctp/sm_sideeffect.c') diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index ce15d590a615..b3815b568e8e 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -471,6 +471,38 @@ out_unlock: sctp_transport_put(transport); } +/* Handle the timeout of the probe timer. */ +void sctp_generate_probe_event(struct timer_list *t) +{ + struct sctp_transport *transport = from_timer(transport, t, probe_timer); + struct sctp_association *asoc = transport->asoc; + struct sock *sk = asoc->base.sk; + struct net *net = sock_net(sk); + int error = 0; + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) { + pr_debug("%s: sock is busy\n", __func__); + + /* Try again later. */ + if (!mod_timer(&transport->probe_timer, jiffies + (HZ / 20))) + sctp_transport_hold(transport); + goto out_unlock; + } + + error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, + SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_PROBE), + asoc->state, asoc->ep, asoc, + transport, GFP_ATOMIC); + + if (error) + sk->sk_err = -error; + +out_unlock: + bh_unlock_sock(sk); + sctp_transport_put(transport); +} + /* Inject a SACK Timeout event into the state machine. */ static void sctp_generate_sack_event(struct timer_list *t) { @@ -1641,6 +1673,11 @@ static int sctp_cmd_interpreter(enum sctp_event_type event_type, sctp_cmd_hb_timers_stop(commands, asoc); break; + case SCTP_CMD_PROBE_TIMER_UPDATE: + t = cmd->obj.transport; + sctp_transport_reset_probe_timer(t); + break; + case SCTP_CMD_REPORT_ERROR: error = cmd->obj.error; break; -- cgit v1.2.3