RDMA/addr: Keep pointer to netdevice in struct rdma_dev_addr

Keep a pointer to the local (src) netdevice in struct rdma_dev_addr,
and copy it in as part of rdma_copy_addr().  Use rdma_translate_ip()
in cma_new_conn_id() to reduce some code duplication and also make
sure the src_dev member gets set.

In a high-availability configuration the netdevice pointer can be used
by the RDMA CM to align RDMA sessions to use the same links as the IP
stack does under fail-over and route change cases.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/addr.c

@@ -105,6 +105,7 @@ int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
 	memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
 	if (dst_dev_addr)
 		memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
+	dev_addr->src_dev = dev;
 	return 0;
 }
 EXPORT_SYMBOL(rdma_copy_addr);

drivers/infiniband/core/cma.c

@@ -1002,6 +1002,7 @@ static struct rdma_id_private *cma_new_conn_id(struct rdma_cm_id *listen_id,
 	union cma_ip_addr *src, *dst;
 	__be16 port;
 	u8 ip_ver;
+	int ret;
 
 	if (cma_get_net_info(ib_event->private_data, listen_id->ps,
 			     &ip_ver, &port, &src, &dst))
@@ -1026,10 +1027,11 @@ static struct rdma_id_private *cma_new_conn_id(struct rdma_cm_id *listen_id,
 	if (rt->num_paths == 2)
 		rt->path_rec[1] = *ib_event->param.req_rcvd.alternate_path;
 
-	ib_addr_set_sgid(&rt->addr.dev_addr, &rt->path_rec[0].sgid);
 	ib_addr_set_dgid(&rt->addr.dev_addr, &rt->path_rec[0].dgid);
-	ib_addr_set_pkey(&rt->addr.dev_addr, be16_to_cpu(rt->path_rec[0].pkey));
-	rt->addr.dev_addr.dev_type = RDMA_NODE_IB_CA;
+	ret = rdma_translate_ip(&id->route.addr.src_addr,
+				&id->route.addr.dev_addr);
+	if (ret)
+		goto destroy_id;
 
 	id_priv = container_of(id, struct rdma_id_private, id);
 	id_priv->state = CMA_CONNECT;

include/rdma/ib_addr.h

@@ -61,6 +61,7 @@ struct rdma_dev_addr {
 	unsigned char dst_dev_addr[MAX_ADDR_LEN];
 	unsigned char broadcast[MAX_ADDR_LEN];
 	enum rdma_node_type dev_type;
+	struct net_device *src_dev;
 };
 
 /**