tipc: propagate peer node capabilities to socket layer

During neighbor discovery, nodes advertise their capabilities as a bit
map in a dedicated 16-bit field in the discovery message header. This
bit map has so far only be stored in the node structure on the peer
nodes, but we now see the need to keep a copy even in the socket
structure.

This commit adds this functionality.

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, 19 insertions, 2 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index c29915688230..29cc85319327 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/node.c: TIPC node management routines
  *
- * Copyright (c) 2000-2006, 2012-2015, Ericsson AB
+ * Copyright (c) 2000-2006, 2012-2016, Ericsson AB
  * Copyright (c) 2005-2006, 2010-2014, Wind River Systems
  * All rights reserved.
  *
@@ -191,6 +191,20 @@ int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel)
         tipc_node_put(n);
         return mtu;
 }
+
+u16 tipc_node_get_capabilities(struct net *net, u32 addr)
+{
+        struct tipc_node *n;
+        u16 caps;
+
+        n = tipc_node_find(net, addr);
+        if (unlikely(!n))
+                return TIPC_NODE_CAPABILITIES;
+        caps = n->capabilities;
+        tipc_node_put(n);
+        return caps;
+}
+
 /*
  * A trivial power-of-two bitmask technique is used for speed, since this
  * operation is done for every incoming TIPC packet. The number of hash table
@@ -304,8 +318,11 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr, u16 capabilities)
 
         spin_lock_bh(&tn->node_list_lock);
         n = tipc_node_find(net, addr);
-        if (n)
+        if (n) {
+                /* Same node may come back with new capabilities */
+                n->capabilities = capabilities;
                 goto exit;
+        }
         n = kzalloc(sizeof(*n), GFP_ATOMIC);
         if (!n) {
                 pr_warn("Node creation failed, no memory\n");