[SCTP] Flag a pmtu change request
Currently, if the socket is owned by the user, we drop the ICMP
message. As a result SCTP forgets that path MTU changed and
never adjusting it's estimate. This causes all subsequent
packets to be fragmented. With this patch, we'll flag the association
that it needs to udpate it's estimate based on the already updated
routing information.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index dda72bf..16baef4 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -503,6 +503,13 @@
return frag;
}
+static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
+{
+
+ sctp_assoc_sync_pmtu(asoc);
+ asoc->pmtu_pending = 0;
+}
+
/* Walk through a list of TLV parameters. Don't trust the
* individual parameter lengths and instead depend on
* the chunk length to indicate when to stop. Make sure
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index dc0e70c..ee4559b 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -912,6 +912,9 @@
*/
__u16 pathmaxrxt;
+ /* is the Path MTU update pending on this tranport */
+ __u8 pmtu_pending;
+
/* PMTU : The current known path MTU. */
__u32 pathmtu;
@@ -1566,6 +1569,9 @@
*/
__u16 pathmaxrxt;
+ /* Flag that path mtu update is pending */
+ __u8 pmtu_pending;
+
/* Association : The smallest PMTU discovered for all of the
* PMTU : peer's transport addresses.
*/
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index df94e3c..498edb0 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1231,6 +1231,10 @@
/* Get the lowest pmtu of all the transports. */
list_for_each(pos, &asoc->peer.transport_addr_list) {
t = list_entry(pos, struct sctp_transport, transports);
+ if (t->pmtu_pending && t->dst) {
+ sctp_transport_update_pmtu(t, dst_mtu(t->dst));
+ t->pmtu_pending = 0;
+ }
if (!pmtu || (t->pathmtu < pmtu))
pmtu = t->pathmtu;
}
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 45d6a64..d57ff7f 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -367,9 +367,15 @@
void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
struct sctp_transport *t, __u32 pmtu)
{
- if (sock_owned_by_user(sk) || !t || (t->pathmtu == pmtu))
+ if (!t || (t->pathmtu == pmtu))
return;
+ if (sock_owned_by_user(sk)) {
+ asoc->pmtu_pending = 1;
+ t->pmtu_pending = 1;
+ return;
+ }
+
if (t->param_flags & SPP_PMTUD_ENABLE) {
/* Update transports view of the MTU */
sctp_transport_update_pmtu(t, pmtu);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 45510c4..6edaaa0 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1662,6 +1662,9 @@
goto out_free;
}
+ if (asoc->pmtu_pending)
+ sctp_assoc_pending_pmtu(asoc);
+
/* If fragmentation is disabled and the message length exceeds the
* association fragmentation point, return EMSGSIZE. The I-D
* does not specify what this error is, but this looks like