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authorXin Long2018-10-15 19:58:29 +0800
committerDavid S. Miller2018-10-15 22:54:20 -0700
commitd805397c3822d57ca3884d4bea37b2291fc40992 (patch)
tree26a590ccde4580779a2428d6071b87bdc967bfae
parentec20a63aa8b8ec3223fb25cdb2a49f9f9dfda88c (diff)
sctp: use the pmtu from the icmp packet to update transport pathmtu
Other than asoc pmtu sync from all transports, sctp_assoc_sync_pmtu is also processing transport pmtu_pending by icmp packets. But it's meaningless to use sctp_dst_mtu(t->dst) as new pmtu for a transport. The right pmtu value should come from the icmp packet, and it would be saved into transport->mtu_info in this patch and used later when the pmtu sync happens in sctp_sendmsg_to_asoc or sctp_packet_config. Besides, without this patch, as pmtu can only be updated correctly when receiving a icmp packet and no place is holding sock lock, it will take long time if the sock is busy with sending packets. Note that it doesn't process transport->mtu_info in .release_cb(), as there is no enough information for pmtu update, like for which asoc or transport. It is not worth traversing all asocs to check pmtu_pending. So unlike tcp, sctp does this in tx path, for which mtu_info needs to be atomic_t. 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>
-rw-r--r--include/net/sctp/structs.h2
-rw-r--r--net/sctp/associola.c3
-rw-r--r--net/sctp/input.c1
-rw-r--r--net/sctp/output.c6
4 files changed, 11 insertions, 1 deletions
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 28a7c8e44636..a11f93790476 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -876,6 +876,8 @@ struct sctp_transport {
unsigned long sackdelay;
__u32 sackfreq;
+ atomic_t mtu_info;
+
/* When was the last time that we heard from this transport? We use
* this to pick new active and retran paths.
*/
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 297d9cf960b9..a827a1f562bf 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1450,7 +1450,8 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
/* Get the lowest pmtu of all the transports. */
list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
if (t->pmtu_pending && t->dst) {
- sctp_transport_update_pmtu(t, sctp_dst_mtu(t->dst));
+ sctp_transport_update_pmtu(t,
+ atomic_read(&t->mtu_info));
t->pmtu_pending = 0;
}
if (!pmtu || (t->pathmtu < pmtu))
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 9bbc5f92c941..5c36a99882ed 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -395,6 +395,7 @@ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
return;
if (sock_owned_by_user(sk)) {
+ atomic_set(&t->mtu_info, pmtu);
asoc->pmtu_pending = 1;
t->pmtu_pending = 1;
return;
diff --git a/net/sctp/output.c b/net/sctp/output.c
index 7f849b01ec8e..67939ad99c01 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -120,6 +120,12 @@ void sctp_packet_config(struct sctp_packet *packet, __u32 vtag,
sctp_assoc_sync_pmtu(asoc);
}
+ if (asoc->pmtu_pending) {
+ if (asoc->param_flags & SPP_PMTUD_ENABLE)
+ sctp_assoc_sync_pmtu(asoc);
+ asoc->pmtu_pending = 0;
+ }
+
/* If there a is a prepend chunk stick it on the list before
* any other chunks get appended.
*/