diff options
author | 2021-06-22 14:04:53 -0400 | |
---|---|---|
committer | 2021-06-22 11:28:52 -0700 | |
commit | 1dc68c194571acc4027de5f8378227d0c0ff7e13 (patch) | |
tree | 502a1b621e23740e42d571aa3c65c336dc144194 /net | |
parent | sctp: do the basic send and recv for PLPMTUD probe (diff) | |
download | linux-1dc68c194571acc4027de5f8378227d0c0ff7e13.tar.gz linux-1dc68c194571acc4027de5f8378227d0c0ff7e13.tar.bz2 linux-1dc68c194571acc4027de5f8378227d0c0ff7e13.zip |
sctp: do state transition when PROBE_COUNT == MAX_PROBES on HB send path
The state transition is described in rfc8899#section-5.2,
PROBE_COUNT == MAX_PROBES means the probe fails for MAX times, and the
state transition includes:
- Base -> Error, occurs when BASE_PLPMTU Confirmation Fails,
pl.pmtu is set to SCTP_MIN_PLPMTU,
probe_size is still SCTP_BASE_PLPMTU;
- Search -> Base, occurs when Black Hole Detected,
pl.pmtu is set to SCTP_BASE_PLPMTU,
probe_size is set back to SCTP_BASE_PLPMTU;
- Search Complete -> Base, occurs when Black Hole Detected
pl.pmtu is set to SCTP_BASE_PLPMTU,
probe_size is set back to SCTP_BASE_PLPMTU;
Note a black hole is encountered when a sender is unaware that packets
are not being delivered to the destination endpoint. So it includes the
probe failures with equal probe_size to pl.pmtu, and definitely not
include that with greater probe_size than pl.pmtu. The later one is the
normal probe failure where probe_size should decrease back to pl.pmtu
and pl.probe_high is set. pl.probe_high would be used on HB ACK recv
path in the next patch.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/sctp/sm_statefuns.c | 2 | ||||
-rw-r--r-- | net/sctp/transport.c | 44 |
2 files changed, 46 insertions, 0 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 8edb9186112a..66c409e5b47c 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -1109,6 +1109,8 @@ enum sctp_disposition sctp_sf_send_probe(struct net *net, if (!sctp_transport_pl_enabled(transport)) return SCTP_DISPOSITION_CONSUME; + sctp_transport_pl_send(transport); + reply = sctp_make_heartbeat(asoc, transport, transport->pl.probe_size); if (!reply) return SCTP_DISPOSITION_NOMEM; diff --git a/net/sctp/transport.c b/net/sctp/transport.c index ca3343c2c80e..99620d86e317 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -261,6 +261,50 @@ void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk) transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT; } +void sctp_transport_pl_send(struct sctp_transport *t) +{ + pr_debug("%s: PLPMTUD: transport: %p, state: %d, pmtu: %d, size: %d, high: %d\n", + __func__, t, t->pl.state, t->pl.pmtu, t->pl.probe_size, t->pl.probe_high); + + if (t->pl.probe_count < SCTP_MAX_PROBES) { + t->pl.probe_count++; + return; + } + + if (t->pl.state == SCTP_PL_BASE) { + if (t->pl.probe_size == SCTP_BASE_PLPMTU) { /* BASE_PLPMTU Confirmation Failed */ + t->pl.state = SCTP_PL_ERROR; /* Base -> Error */ + + t->pl.pmtu = SCTP_MIN_PLPMTU; + t->pathmtu = t->pl.pmtu + sctp_transport_pl_hlen(t); + sctp_assoc_sync_pmtu(t->asoc); + } + } else if (t->pl.state == SCTP_PL_SEARCH) { + if (t->pl.pmtu == t->pl.probe_size) { /* Black Hole Detected */ + t->pl.state = SCTP_PL_BASE; /* Search -> Base */ + t->pl.probe_size = SCTP_BASE_PLPMTU; + t->pl.probe_high = 0; + + t->pl.pmtu = SCTP_BASE_PLPMTU; + t->pathmtu = t->pl.pmtu + sctp_transport_pl_hlen(t); + sctp_assoc_sync_pmtu(t->asoc); + } else { /* Normal probe failure. */ + t->pl.probe_high = t->pl.probe_size; + t->pl.probe_size = t->pl.pmtu; + } + } else if (t->pl.state == SCTP_PL_COMPLETE) { + if (t->pl.pmtu == t->pl.probe_size) { /* Black Hole Detected */ + t->pl.state = SCTP_PL_BASE; /* Search Complete -> Base */ + t->pl.probe_size = SCTP_BASE_PLPMTU; + + t->pl.pmtu = SCTP_BASE_PLPMTU; + t->pathmtu = t->pl.pmtu + sctp_transport_pl_hlen(t); + sctp_assoc_sync_pmtu(t->asoc); + } + } + t->pl.probe_count = 1; +} + bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu) { struct dst_entry *dst = sctp_transport_dst_check(t); |