Merge branch 'tipc-next'

Jon Maloy says:

====================
tipc: improve broadcast implementation

The TIPC broadcast link implementation is currently complex and hard to
follow. It also incurs some amount of code and structure duplication,
something that can be reduced significantly with a little effort.

This commit series introduces a number of improvements which address
both the locking structure, the code/structure duplication issue, and
the overall readbility of the code.

The series consists of three main parts:

1-7: Adaptation to the new link structure, and preparation for the next
     step. In particular, we want the broadcast transmission link to
     have a life cycle that is longer than any of its potential (unicast
     and broadcast receive links) users. This eliminates the need to
     always test for the presence of this link before accessing it.

8-10: This is what is really new in this series. Commit #9 is by far
      the largest and most important one, because it moves most of
      the broadcast functionality into link.c, partially reusing the
      fields and functionality of the unicast link. The removal of
      the "node_map" infrastructure in commit #10 is also an important
      achievement.

11-16: Some improvements leveraging the changes made in the previous
       commits.

The series needs commit 53387c4e22ac ("tipc: extend broadcast link window size")
and commit e53567948f82 ("tipc: conditionally expand buffer headroom over udp tunnel")
which are both present in 'net' but not yet in 'net-next', to apply cleanly.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 59 insertions, 35 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 82b278668ab7..648f2a67f314 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -193,10 +193,8 @@ void tipc_bearer_add_dest(struct net *net, u32 bearer_id, u32 dest)
 
 	rcu_read_lock();
 	b_ptr = rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
-	if (b_ptr) {
-		tipc_bcbearer_sort(net, &b_ptr->nodes, dest, true);
+	if (b_ptr)
 		tipc_disc_add_dest(b_ptr->link_req);
-	}
 	rcu_read_unlock();
 }
 
@@ -207,10 +205,8 @@ void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
 
 	rcu_read_lock();
 	b_ptr = rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
-	if (b_ptr) {
-		tipc_bcbearer_sort(net, &b_ptr->nodes, dest, false);
+	if (b_ptr)
 		tipc_disc_remove_dest(b_ptr->link_req);
-	}
 	rcu_read_unlock();
 }
 
@@ -418,10 +414,9 @@ void tipc_disable_l2_media(struct tipc_bearer *b)
  * @b_ptr: the bearer through which the packet is to be sent
  * @dest: peer destination address
  */
-int tipc_l2_send_msg(struct net *net, struct sk_buff *buf,
+int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
 		     struct tipc_bearer *b, struct tipc_media_addr *dest)
 {
-	struct sk_buff *clone;
 	struct net_device *dev;
 	int delta;
 
@@ -429,42 +424,48 @@ int tipc_l2_send_msg(struct net *net, struct sk_buff *buf,
 	if (!dev)
 		return 0;
 
-	clone = skb_clone(buf, GFP_ATOMIC);
-	if (!clone)
-		return 0;
-
-	delta = dev->hard_header_len - skb_headroom(buf);
+	delta = dev->hard_header_len - skb_headroom(skb);
 	if ((delta > 0) &&
-	    pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
-		kfree_skb(clone);
+	    pskb_expand_head(skb, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
+		kfree_skb(skb);
 		return 0;
 	}
 
-	skb_reset_network_header(clone);
-	clone->dev = dev;
-	clone->protocol = htons(ETH_P_TIPC);
-	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
-			dev->dev_addr, clone->len);
-	dev_queue_xmit(clone);
+	skb_reset_network_header(skb);
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_TIPC);
+	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
+			dev->dev_addr, skb->len);
+	dev_queue_xmit(skb);
 	return 0;
 }
 
-/* tipc_bearer_send- sends buffer to destination over bearer
- *
- * IMPORTANT:
- * The media send routine must not alter the buffer being passed in
- * as it may be needed for later retransmission!
+int tipc_bearer_mtu(struct net *net, u32 bearer_id)
+{
+	int mtu = 0;
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = rcu_dereference_rtnl(tipc_net(net)->bearer_list[bearer_id]);
+	if (b)
+		mtu = b->mtu;
+	rcu_read_unlock();
+	return mtu;
+}
+
+/* tipc_bearer_xmit_skb - sends buffer to destination over bearer
  */
-void tipc_bearer_send(struct net *net, u32 bearer_id, struct sk_buff *buf,
-		      struct tipc_media_addr *dest)
+void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
+			  struct sk_buff *skb,
+			  struct tipc_media_addr *dest)
 {
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
-	struct tipc_bearer *b_ptr;
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_bearer *b;
 
 	rcu_read_lock();
-	b_ptr = rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
-	if (likely(b_ptr))
-		b_ptr->media->send_msg(net, buf, b_ptr, dest);
+	b = rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
+	if (likely(b))
+		b->media->send_msg(net, skb, b, dest);
 	rcu_read_unlock();
 }
 
@@ -487,8 +488,31 @@ void tipc_bearer_xmit(struct net *net, u32 bearer_id,
 		skb_queue_walk_safe(xmitq, skb, tmp) {
 			__skb_dequeue(xmitq);
 			b->media->send_msg(net, skb, b, dst);
-			/* Until we remove cloning in tipc_l2_send_msg(): */
-			kfree_skb(skb);
+		}
+	}
+	rcu_read_unlock();
+}
+
+/* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
+ */
+void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
+			 struct sk_buff_head *xmitq)
+{
+	struct tipc_net *tn = tipc_net(net);
+	int net_id = tn->net_id;
+	struct tipc_bearer *b;
+	struct sk_buff *skb, *tmp;
+	struct tipc_msg *hdr;
+
+	rcu_read_lock();
+	b = rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
+	if (likely(b)) {
+		skb_queue_walk_safe(xmitq, skb, tmp) {
+			hdr = buf_msg(skb);
+			msg_set_non_seq(hdr, 1);
+			msg_set_mc_netid(hdr, net_id);
+			__skb_dequeue(xmitq);
+			b->media->send_msg(net, skb, b, &b->bcast_addr);
 		}
 	}
 	rcu_read_unlock();