Neil Horman <nhorman@xxxxxxxxxxxxx> 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 <nhorman@xxxxxxxxxxxxx> >CC: Vlad Yasevich <vyasevich@xxxxxxxxx> >CC: Sridhar Samudrala <sri@xxxxxxxxxx> >CC: "David S. Miller" <davem@xxxxxxxxxxxxx> >CC: linux-sctp@xxxxxxxxxxxxxxx >CC: joe@xxxxxxxxxxx > >--- >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(-) > >> /* 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; I don't think you can simply return this. You have to call put_user() with the value to write it back to the User. See how other get calls are done. -Vlad >+} >+ >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; >-- >1.7.7.6 -- Sent from my Android phone with SkitMail. 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