tipc: confgiure and apply UDP bearer MTU on running links

Currently, we have option to configure MTU of UDP media. The configured
MTU takes effect on the links going up after that moment. I.e, a user
has to reset bearer to have new value applied across its links. This is
confusing and disturbing on a running cluster.

We now introduce the functionality to change the default UDP bearer MTU
in struct tipc_bearer. Additionally, the links are updated dynamically,
without any need for a reset, when bearer value is changed. We leverage
the existing per-link functionality and the design being symetrical to
the confguration of link tolerance.

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 1 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index a22caf9e5a18..2dfb492a7c94 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -697,6 +697,9 @@ static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
                 goto prop_msg_full;
         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->window))
                 goto prop_msg_full;
+        if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
+                if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
+                        goto prop_msg_full;
 
         nla_nest_end(msg->skb, prop);
 
@@ -979,12 +982,23 @@ int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
 
                 if (props[TIPC_NLA_PROP_TOL]) {
                         b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
-                        tipc_node_apply_tolerance(net, b);
+                        tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
                 }
                 if (props[TIPC_NLA_PROP_PRIO])
                         b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
                 if (props[TIPC_NLA_PROP_WIN])
                         b->window = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
+                if (props[TIPC_NLA_PROP_MTU]) {
+                        if (b->media->type_id != TIPC_MEDIA_TYPE_UDP)
+                                return -EINVAL;
+#ifdef CONFIG_TIPC_MEDIA_UDP
+                        if (tipc_udp_mtu_bad(nla_get_u32
+                                             (props[TIPC_NLA_PROP_MTU])))
+                                return -EINVAL;
+                        b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
+                        tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
+#endif
+                }
         }
 
         return 0;