tipc: Add support for customized subscription overlap handling

This patch enables TIPC's topology server code to do customized
overlap detection handling on a per-subscription basis.  (This
capability is needed to support the upcoming introduction of
multi-cluster TIPC networks.)

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 1 deletions

diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
index 8f8d0a6c1c16..81e2bd5f2413 100644
--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -157,7 +157,8 @@ void tipc_subscr_report_overlap(struct subscription *sub,
                 return;
         if (!must && !(sub->filter & TIPC_SUB_PORTS))
                 return;
-        subscr_send_event(sub, found_lower, found_upper, event, port_ref, node);
+
+        sub->event_cb(sub, found_lower, found_upper, event, port_ref, node);
 }
 
 /**
@@ -372,6 +373,7 @@ static void subscr_subscribe(struct tipc_subscr *s,
                 subscr_terminate(subscriber);
                 return;
         }
+        sub->event_cb = subscr_send_event;
         memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
         INIT_LIST_HEAD(&sub->subscription_list);
         INIT_LIST_HEAD(&sub->nameseq_list);
diff --git a/net/tipc/subscr.h b/net/tipc/subscr.h
index 93a8e674fac1..d95536832907 100644
--- a/net/tipc/subscr.h
+++ b/net/tipc/subscr.h
@@ -37,11 +37,18 @@
 #ifndef _TIPC_SUBSCR_H
 #define _TIPC_SUBSCR_H
 
+struct subscription;
+
+typedef void (*tipc_subscr_event) (struct subscription *sub,
+                                   u32 found_lower, u32 found_upper,
+                                   u32 event, u32 port_ref, u32 node);
+
 /**
  * struct subscription - TIPC network topology subscription object
  * @seq: name sequence associated with subscription
  * @timeout: duration of subscription (in ms)
  * @filter: event filtering to be done for subscription
+ * @event_cb: routine invoked when a subscription event is detected
  * @evt: template for events generated by subscription
  * @subscription_list: adjacent subscriptions in subscriber's subscription list
  * @nameseq_list: adjacent subscriptions in name sequence's subscription list
@@ -53,6 +60,7 @@ struct subscription {
         struct tipc_name_seq seq;
         u32 timeout;
         u32 filter;
+        tipc_subscr_event event_cb;
         struct tipc_event evt;
         struct list_head subscription_list;
         struct list_head nameseq_list;