tipc: improve groupcast scope handling

When a member joins a group, it also indicates a binding scope. This
makes it possible to create both node local groups, invisible to other
nodes, as well as cluster global groups, visible everywhere.

In order to avoid that different members end up having permanently
differing views of group size and memberhip, we must inhibit locally
and globally bound members from joining the same group.

We do this by using the binding scope as an additional separator between
groups. I.e., a member must ignore all membership events from sockets
using a different scope than itself, and all lookups for message
destinations must require an exact match between the message's lookup
scope and the potential target's binding scope.

Apart from making it possible to create local groups using the same
identity on different nodes, a side effect of this is that it now also
becomes possible to create a cluster global group with the same identity
across the same nodes, without interfering with the local groups.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 5 deletions

diff --git a/net/tipc/group.c b/net/tipc/group.c
index cf996bd6ec98..1908773c9fca 100644
--- a/net/tipc/group.c
+++ b/net/tipc/group.c
@@ -87,7 +87,6 @@ struct tipc_group {
 	int subid;
 	u32 type;
 	u32 instance;
-	u32 domain;
 	u32 scope;
 	u32 portid;
 	u16 member_cnt;
@@ -158,6 +157,8 @@ int tipc_group_size(struct tipc_group *grp)
 struct tipc_group *tipc_group_create(struct net *net, u32 portid,
 				     struct tipc_group_req *mreq)
 {
+	u32 filter = TIPC_SUB_PORTS | TIPC_SUB_NO_STATUS;
+	bool global = mreq->scope != TIPC_NODE_SCOPE;
 	struct tipc_group *grp;
 	u32 type = mreq->type;
 
@@ -171,15 +172,14 @@ struct tipc_group *tipc_group_create(struct net *net, u32 portid,
 	grp->members = RB_ROOT;
 	grp->net = net;
 	grp->portid = portid;
-	grp->domain = addr_domain(net, mreq->scope);
 	grp->type = type;
 	grp->instance = mreq->instance;
 	grp->scope = mreq->scope;
 	grp->loopback = mreq->flags & TIPC_GROUP_LOOPBACK;
 	grp->events = mreq->flags & TIPC_GROUP_MEMBER_EVTS;
-	if (tipc_topsrv_kern_subscr(net, portid, type,
-				    TIPC_SUB_PORTS | TIPC_SUB_NO_STATUS,
-				    0, ~0, &grp->subid))
+	filter |= global ? TIPC_SUB_CLUSTER_SCOPE : TIPC_SUB_NODE_SCOPE;
+	if (tipc_topsrv_kern_subscr(net, portid, type, 0, ~0,
+				    filter, &grp->subid))
 		return grp;
 	kfree(grp);
 	return NULL;
@@ -732,6 +732,9 @@ void tipc_group_proto_rcv(struct tipc_group *grp, bool *usr_wakeup,
 	if (!grp)
 		return;
 
+	if (grp->scope == TIPC_NODE_SCOPE && node != tipc_own_addr(grp->net))
+		return;
+
 	m = tipc_group_find_member(grp, node, port);
 
 	switch (msg_type(hdr)) {