tipc: reduce code dependency between binding table and node layer

The file name_distr.c currently contains three functions,
named_cluster_distribute(), tipc_publ_subcscribe() and
tipc_publ_unsubscribe() that all directly access fields in
struct tipc_node. We want to eliminate such dependencies, so
we move those functions to the file node.c and rename them to
tipc_node_broadcast(), tipc_node_subscribe() and tipc_node_unsubscribe()
respectively.

Reviewed-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>

net/tipc/core.h

@@ -118,6 +118,11 @@ static inline int tipc_netid(struct net *net)
 	return tipc_net(net)->net_id;
 }
 
+static inline struct list_head *tipc_nodes(struct net *net)
+{
+	return &tipc_net(net)->node_list;
+}
+
 static inline u16 mod(u16 x)
 {
 	return x & 0xffffu;

net/tipc/name_distr.c

@@ -84,31 +84,6 @@ static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
 	return buf;
 }
 
-void named_cluster_distribute(struct net *net, struct sk_buff *skb)
-{
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
-	struct sk_buff *oskb;
-	struct tipc_node *node;
-	u32 dnode;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(node, &tn->node_list, list) {
-		dnode = node->addr;
-		if (in_own_node(net, dnode))
-			continue;
-		if (!tipc_node_is_up(node))
-			continue;
-		oskb = pskb_copy(skb, GFP_ATOMIC);
-		if (!oskb)
-			break;
-		msg_set_destnode(buf_msg(oskb), dnode);
-		tipc_node_xmit_skb(net, oskb, dnode, 0);
-	}
-	rcu_read_unlock();
-
-	kfree_skb(skb);
-}
-
 /**
  * tipc_named_publish - tell other nodes about a new publication by this node
  */
@@ -226,42 +201,6 @@ void tipc_named_node_up(struct net *net, u32 dnode)
 	tipc_node_xmit(net, &head, dnode, 0);
 }
 
-static void tipc_publ_subscribe(struct net *net, struct publication *publ,
-				u32 addr)
-{
-	struct tipc_node *node;
-
-	if (in_own_node(net, addr))
-		return;
-
-	node = tipc_node_find(net, addr);
-	if (!node) {
-		pr_warn("Node subscription rejected, unknown node 0x%x\n",
-			addr);
-		return;
-	}
-
-	tipc_node_lock(node);
-	list_add_tail(&publ->nodesub_list, &node->publ_list);
-	tipc_node_unlock(node);
-	tipc_node_put(node);
-}
-
-static void tipc_publ_unsubscribe(struct net *net, struct publication *publ,
-				  u32 addr)
-{
-	struct tipc_node *node;
-
-	node = tipc_node_find(net, addr);
-	if (!node)
-		return;
-
-	tipc_node_lock(node);
-	list_del_init(&publ->nodesub_list);
-	tipc_node_unlock(node);
-	tipc_node_put(node);
-}
-
 /**
  * tipc_publ_purge - remove publication associated with a failed node
  *
@@ -277,7 +216,7 @@ static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
 	p = tipc_nametbl_remove_publ(net, publ->type, publ->lower,
 				     publ->node, publ->ref, publ->key);
 	if (p)
-		tipc_publ_unsubscribe(net, p, addr);
+		tipc_node_unsubscribe(net, &p->nodesub_list, addr);
 	spin_unlock_bh(&tn->nametbl_lock);
 
 	if (p != publ) {
@@ -317,7 +256,7 @@ static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 						TIPC_CLUSTER_SCOPE, node,
 						ntohl(i->ref), ntohl(i->key));
 		if (publ) {
-			tipc_publ_subscribe(net, publ, node);
+			tipc_node_subscribe(net, &publ->nodesub_list, node);
 			return true;
 		}
 	} else if (dtype == WITHDRAWAL) {
@@ -326,7 +265,7 @@ static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 						node, ntohl(i->ref),
 						ntohl(i->key));
 		if (publ) {
-			tipc_publ_unsubscribe(net, publ, node);
+			tipc_node_unsubscribe(net, &publ->nodesub_list, node);
 			kfree_rcu(publ, rcu);
 			return true;
 		}

net/tipc/name_distr.h

@@ -69,7 +69,6 @@ struct distr_item {
 
 struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ);
 struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ);
-void named_cluster_distribute(struct net *net, struct sk_buff *buf);
 void tipc_named_node_up(struct net *net, u32 dnode);
 void tipc_named_rcv(struct net *net, struct sk_buff_head *msg_queue);
 void tipc_named_reinit(struct net *net);

net/tipc/name_table.c

@@ -42,6 +42,7 @@
 #include "subscr.h"
 #include "bcast.h"
 #include "addr.h"
+#include "node.h"
 #include <net/genetlink.h>
 
 #define TIPC_NAMETBL_SIZE 1024		/* must be a power of 2 */
@@ -677,7 +678,7 @@ struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
 	spin_unlock_bh(&tn->nametbl_lock);
 
 	if (buf)
-		named_cluster_distribute(net, buf);
+		tipc_node_broadcast(net, buf);
 	return publ;
 }
 
@@ -709,7 +710,7 @@ int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower, u32 ref,
 	spin_unlock_bh(&tn->nametbl_lock);
 
 	if (skb) {
-		named_cluster_distribute(net, skb);
+		tipc_node_broadcast(net, skb);
 		return 1;
 	}
 	return 0;

net/tipc/node.c

@@ -234,6 +234,42 @@ void tipc_node_stop(struct net *net)
 	spin_unlock_bh(&tn->node_list_lock);
 }
 
+void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
+{
+	struct tipc_node *n;
+
+	if (in_own_node(net, addr))
+		return;
+
+	n = tipc_node_find(net, addr);
+	if (!n) {
+		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
+		return;
+	}
+	tipc_node_lock(n);
+	list_add_tail(subscr, &n->publ_list);
+	tipc_node_unlock(n);
+	tipc_node_put(n);
+}
+
+void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
+{
+	struct tipc_node *n;
+
+	if (in_own_node(net, addr))
+		return;
+
+	n = tipc_node_find(net, addr);
+	if (!n) {
+		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
+		return;
+	}
+	tipc_node_lock(n);
+	list_del_init(subscr);
+	tipc_node_unlock(n);
+	tipc_node_put(n);
+}
+
 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
 {
 	struct tipc_node *node;
@@ -1075,6 +1111,30 @@ int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 	return 0;
 }
 
+void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
+{
+	struct sk_buff *txskb;
+	struct tipc_node *n;
+	u32 dst;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
+		dst = n->addr;
+		if (in_own_node(net, dst))
+			continue;
+		if (!tipc_node_is_up(n))
+			continue;
+		txskb = pskb_copy(skb, GFP_ATOMIC);
+		if (!txskb)
+			break;
+		msg_set_destnode(buf_msg(txskb), dst);
+		tipc_node_xmit_skb(net, txskb, dst, 0);
+	}
+	rcu_read_unlock();
+
+	kfree_skb(skb);
+}
+
 /**
  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
  * @net: the applicable net namespace

net/tipc/node.h

@@ -149,6 +149,9 @@ int tipc_node_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 		   int selector);
 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dest,
 		       u32 selector);
+void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr);
+void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr);
+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_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb);