tipc: add new functions for multicast and broadcast distribution

We add a new broadcast link transmit function in bclink.c and a new
receive function in socket.c. The purpose is to move the branching
between external and internal destination down to the link layer,
just as we have done with unicast in earlier commits. We also make
use of the new link-independent fragmentation support that was
introduced in an earlier commit series.

This gives a shorter and simpler code path, and makes it possible
to obtain copy-free buffer delivery to all node local destination
sockets.

The new transmission code is added in parallel with the existing one,
and will be used by the socket multicast send function in the next
commit in this series.

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

1 files changed, 40 insertions, 0 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index de01622672b2..8d30995682b1 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -534,6 +534,46 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 	return mask;
 }
 
+/* tipc_sk_mcast_rcv - Deliver multicast message to all destination sockets
+ */
+void tipc_sk_mcast_rcv(struct sk_buff *buf)
+{
+	struct tipc_msg *msg = buf_msg(buf);
+	struct tipc_port_list dports = {0, NULL, };
+	struct tipc_port_list *item;
+	struct sk_buff *b;
+	uint i, last, dst = 0;
+	u32 scope = TIPC_CLUSTER_SCOPE;
+
+	if (in_own_node(msg_orignode(msg)))
+		scope = TIPC_NODE_SCOPE;
+
+	/* Create destination port list: */
+	tipc_nametbl_mc_translate(msg_nametype(msg),
+				  msg_namelower(msg),
+				  msg_nameupper(msg),
+				  scope,
+				  &dports);
+	last = dports.count;
+	if (!last) {
+		kfree_skb(buf);
+		return;
+	}
+
+	for (item = &dports; item; item = item->next) {
+		for (i = 0; i < PLSIZE && ++dst <= last; i++) {
+			b = (dst != last) ? skb_clone(buf, GFP_ATOMIC) : buf;
+			if (!b) {
+				pr_warn("Failed do clone mcast rcv buffer\n");
+				continue;
+			}
+			msg_set_destport(msg, item->ports[i]);
+			tipc_sk_rcv(b);
+		}
+	}
+	tipc_port_list_free(&dports);
+}
+
 /**
  * tipc_sk_proto_rcv - receive a connection mng protocol message
  * @tsk: receiving socket