tipc: add ability to obtain node availability status from other files

In the coming commits, functions at the socket level will need the
ability to read the availability status of a given node. We therefore
introduce a new function for this purpose, while renaming the existing
static function currently having the wanted name.

Signed-off-by: Jon Maloy <[email protected]>
Acked-by: Ying Xue <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Jon Maloy

net/tipc/node.c

@@ -157,7 +157,7 @@ static void tipc_node_timeout(unsigned long data);
 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
 static void tipc_node_put(struct tipc_node *node);
-static bool tipc_node_is_up(struct tipc_node *n);
+static bool node_is_up(struct tipc_node *n);
 
 struct tipc_sock_conn {
 	u32 port;
@@ -657,7 +657,7 @@ static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
 		*slot1 = i;
 	}
 
-	if (!tipc_node_is_up(n)) {
+	if (!node_is_up(n)) {
 		if (tipc_link_peer_is_down(l))
 			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
 		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
@@ -717,11 +717,27 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
 	tipc_sk_rcv(n->net, &le->inputq);
 }
 
-static bool tipc_node_is_up(struct tipc_node *n)
+static bool node_is_up(struct tipc_node *n)
 {
 	return n->active_links[0] != INVALID_BEARER_ID;
 }
 
+bool tipc_node_is_up(struct net *net, u32 addr)
+{
+	struct tipc_node *n;
+	bool retval = false;
+
+	if (in_own_node(net, addr))
+		return true;
+
+	n = tipc_node_find(net, addr);
+	if (!n)
+		return false;
+	retval = node_is_up(n);
+	tipc_node_put(n);
+	return retval;
+}
+
 void tipc_node_check_dest(struct net *net, u32 onode,
 			  struct tipc_bearer *b,
 			  u16 capabilities, u32 signature,
@@ -1149,7 +1165,7 @@ static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
 
 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
 		goto attr_msg_full;
-	if (tipc_node_is_up(node))
+	if (node_is_up(node))
 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
 			goto attr_msg_full;
 
@@ -1249,7 +1265,7 @@ void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
 		dst = n->addr;
 		if (in_own_node(net, dst))
 			continue;
-		if (!tipc_node_is_up(n))
+		if (!node_is_up(n))
 			continue;
 		txskb = pskb_copy(skb, GFP_ATOMIC);
 		if (!txskb)

net/tipc/node.h

@@ -76,6 +76,7 @@ void tipc_node_broadcast(struct net *net, struct sk_buff *skb);
 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port);
 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port);
 int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel);
+bool tipc_node_is_up(struct net *net, u32 addr);
 u16 tipc_node_get_capabilities(struct net *net, u32 addr);
 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb);