tipc: add support for link state subscriptions

When links are established over a bearer plane, we create a node
local publication containing information about the peer node and
bearer plane. This allows TIPC applications to use the standard
TIPC topology server subscription mechanism to get notifications
when a link goes up or down.

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

diff --git a/include/uapi/linux/tipc.h b/include/uapi/linux/tipc.h
index 852373d..53cd790 100644 (file)
--- a/include/uapi/linux/tipc.h
+++ b/include/uapi/linux/tipc.h
@@ -87,6 +87,7 @@ static inline unsigned int tipc_node(__u32 addr)
 
 #define TIPC_CFG_SRV           0       /* configuration service name type */
 #define TIPC_TOP_SRV           1       /* topology service name type */
+#define TIPC_LINK_STATE                2       /* link state name type */
 #define TIPC_RESERVED_TYPES    64      /* lowest user-publishable name type */
 
 /*

diff --git a/net/tipc/node.c b/net/tipc/node.c
index be90115..3b86a74 100644 (file)
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -144,9 +144,11 @@ void tipc_node_stop(void)
 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 {
        struct tipc_link **active = &n_ptr->active_links[0];
+       u32 addr = n_ptr->addr;
 
        n_ptr->working_links++;
-
+       tipc_nametbl_publish(TIPC_LINK_STATE, addr, addr, TIPC_NODE_SCOPE,
+                            l_ptr->bearer_id, addr);
        pr_info("Established link <%s> on network plane %c\n",
                l_ptr->name, l_ptr->net_plane);
 
@@ -203,8 +205,10 @@ static void node_select_active_links(struct tipc_node *n_ptr)
 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 {
        struct tipc_link **active;
+       u32 addr = n_ptr->addr;
 
        n_ptr->working_links--;
+       tipc_nametbl_withdraw(TIPC_LINK_STATE, addr, l_ptr->bearer_id, addr);
 
        if (!tipc_link_is_active(l_ptr)) {
                pr_info("Lost standby link <%s> on network plane %c\n",