tipc: allow rdm/dgram socketpairs

for socketpairs using connectionless transport, we cache
the respective node local TIPC portid to use in subsequent
calls to send() in the socket's private data.
Signed-off-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/socket.c

@@ -2515,9 +2515,21 @@ static int tipc_socketpair(struct socket *sock1, struct socket *sock2)
 {
 	struct tipc_sock *tsk2 = tipc_sk(sock2->sk);
 	struct tipc_sock *tsk1 = tipc_sk(sock1->sk);
-
-	tipc_sk_finish_conn(tsk1, tsk2->portid, 0);
-	tipc_sk_finish_conn(tsk2, tsk1->portid, 0);
+	u32 onode = tipc_own_addr(sock_net(sock1->sk));
+
+	tsk1->peer.family = AF_TIPC;
+	tsk1->peer.addrtype = TIPC_ADDR_ID;
+	tsk1->peer.scope = TIPC_NODE_SCOPE;
+	tsk1->peer.addr.id.ref = tsk2->portid;
+	tsk1->peer.addr.id.node = onode;
+	tsk2->peer.family = AF_TIPC;
+	tsk2->peer.addrtype = TIPC_ADDR_ID;
+	tsk2->peer.scope = TIPC_NODE_SCOPE;
+	tsk2->peer.addr.id.ref = tsk1->portid;
+	tsk2->peer.addr.id.node = onode;
+
+	tipc_sk_finish_conn(tsk1, tsk2->portid, onode);
+	tipc_sk_finish_conn(tsk2, tsk1->portid, onode);
 	return 0;
 }
 
@@ -2529,7 +2541,7 @@ static const struct proto_ops msg_ops = {
 	.release	= tipc_release,
 	.bind		= tipc_bind,
 	.connect	= tipc_connect,
-	.socketpair	= sock_no_socketpair,
+	.socketpair	= tipc_socketpair,
 	.accept		= sock_no_accept,
 	.getname	= tipc_getname,
 	.poll		= tipc_poll,