[net-next 2/3] tipc: introduce new capability flag for cluster

[Hoang Le <hoang.h.le@dektech.com.au>]

As a preparation for introducing a moothly switching between replicast
and broadcast method for multicast message. We have to introduce a new
capability flag TIPC_MCAST_RBCTL to handle this new feature because of
compatibility reasons.
When a cluster upgrade a node can come back with this new capabilities
which also must be reflected in the cluster capabilities field and new
feature only applicable if the cluster supports this new capability.

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
---
 net/tipc/core.c |  2 ++
 net/tipc/core.h |  3 +++
 net/tipc/node.c | 18 ++++++++++++++++++
 net/tipc/node.h |  6 ++++--
 4 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/net/tipc/core.c b/net/tipc/core.c
index 5b38f5164281..27cccd101ef6 100644
--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -43,6 +43,7 @@
 #include "net.h"
 #include "socket.h"
 #include "bcast.h"
+#include "node.h"
 
 #include <linux/module.h>
 
@@ -59,6 +60,7 @@ static int __net_init tipc_init_net(struct net *net)
 	tn->node_addr = 0;
 	tn->trial_addr = 0;
 	tn->addr_trial_end = 0;
+	tn->capabilities = TIPC_NODE_CAPABILITIES;
 	memset(tn->node_id, 0, sizeof(tn->node_id));
 	memset(tn->node_id_string, 0, sizeof(tn->node_id_string));
 	tn->mon_threshold = TIPC_DEF_MON_THRESHOLD;
diff --git a/net/tipc/core.h b/net/tipc/core.h
index 8020a6c360ff..7a68e1b6a066 100644
--- a/net/tipc/core.h
+++ b/net/tipc/core.h
@@ -122,6 +122,9 @@ struct tipc_net {
 	/* Topology subscription server */
 	struct tipc_topsrv *topsrv;
 	atomic_t subscription_count;
+
+	/* Cluster capabilities */
+	u16 capabilities;
 };
 
 static inline struct tipc_net *tipc_net(struct net *net)
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 2dc4919ab23c..2717893e9dbe 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -383,6 +383,11 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
 				tipc_link_update_caps(l, capabilities);
 		}
 		write_unlock_bh(&n->lock);
+		/* Calculate cluster capabilities */
+		tn->capabilities = TIPC_NODE_CAPABILITIES;
+		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
+			tn->capabilities &= temp_node->capabilities;
+		}
 		goto exit;
 	}
 	n = kzalloc(sizeof(*n), GFP_ATOMIC);
@@ -433,6 +438,11 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
 			break;
 	}
 	list_add_tail_rcu(&n->list, &temp_node->list);
+	/* Calculate cluster capabilities */
+	tn->capabilities = TIPC_NODE_CAPABILITIES;
+	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
+		tn->capabilities &= temp_node->capabilities;
+	}
 	trace_tipc_node_create(n, true, " ");
 exit:
 	spin_unlock_bh(&tn->node_list_lock);
@@ -589,6 +599,7 @@ static void  tipc_node_clear_links(struct tipc_node *node)
  */
 static bool tipc_node_cleanup(struct tipc_node *peer)
 {
+	struct tipc_node *temp_node;
 	struct tipc_net *tn = tipc_net(peer->net);
 	bool deleted = false;
 
@@ -604,6 +615,13 @@ static bool tipc_node_cleanup(struct tipc_node *peer)
 		deleted = true;
 	}
 	tipc_node_write_unlock(peer);
+
+	/* Calculate cluster capabilities */
+	tn->capabilities = TIPC_NODE_CAPABILITIES;
+	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
+		tn->capabilities &= temp_node->capabilities;
+	}
+
 	spin_unlock_bh(&tn->node_list_lock);
 	return deleted;
 }
diff --git a/net/tipc/node.h b/net/tipc/node.h
index 4f59a30e989a..2404225c5d58 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -51,7 +51,8 @@ enum {
 	TIPC_BLOCK_FLOWCTL    = (1 << 3),
 	TIPC_BCAST_RCAST      = (1 << 4),
 	TIPC_NODE_ID128       = (1 << 5),
-	TIPC_LINK_PROTO_SEQNO = (1 << 6)
+	TIPC_LINK_PROTO_SEQNO = (1 << 6),
+	TIPC_MCAST_RBCTL      = (1 << 7)
 };
 
 #define TIPC_NODE_CAPABILITIES (TIPC_SYN_BIT           |  \
@@ -60,7 +61,8 @@ enum {
 				TIPC_BCAST_RCAST       |   \
 				TIPC_BLOCK_FLOWCTL     |   \
 				TIPC_NODE_ID128        |   \
-				TIPC_LINK_PROTO_SEQNO)
+				TIPC_LINK_PROTO_SEQNO  |   \
+				TIPC_MCAST_RBCTL)
 #define INVALID_BEARER_ID -1
 
 void tipc_node_stop(struct net *net);
-- 
2.17.1