RDMA/nldev: Provide netdevice name and index

Export the net device name and index to easily find connection
between IB devices and relevant net devices.

We also updated the comment regarding the devices without FW.
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/nldev.c

@@ -95,6 +95,9 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
 	[RDMA_NLDEV_ATTR_RES_PD_ENTRY]		= { .type = NLA_NESTED },
 	[RDMA_NLDEV_ATTR_RES_LOCAL_DMA_LKEY]	= { .type = NLA_U32 },
 	[RDMA_NLDEV_ATTR_RES_UNSAFE_GLOBAL_RKEY] = { .type = NLA_U32 },
+	[RDMA_NLDEV_ATTR_NDEV_INDEX]		= { .type = NLA_U32 },
+	[RDMA_NLDEV_ATTR_NDEV_NAME]		= { .type = NLA_NUL_STRING,
+						    .len = IFNAMSIZ },
 };
 
 static int fill_nldev_handle(struct sk_buff *msg, struct ib_device *device)
@@ -123,7 +126,7 @@ static int fill_dev_info(struct sk_buff *msg, struct ib_device *device)
 		return -EMSGSIZE;
 
 	ib_get_device_fw_str(device, fw);
-	/* Device without FW has strlen(fw) */
+	/* Device without FW has strlen(fw) = 0 */
 	if (strlen(fw) && nla_put_string(msg, RDMA_NLDEV_ATTR_FW_VERSION, fw))
 		return -EMSGSIZE;
 
@@ -139,8 +142,10 @@ static int fill_dev_info(struct sk_buff *msg, struct ib_device *device)
 }
 
 static int fill_port_info(struct sk_buff *msg,
-			  struct ib_device *device, u32 port)
+			  struct ib_device *device, u32 port,
+			  const struct net *net)
 {
+	struct net_device *netdev = NULL;
 	struct ib_port_attr attr;
 	int ret;
 
@@ -174,7 +179,23 @@ static int fill_port_info(struct sk_buff *msg,
 		return -EMSGSIZE;
 	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_PORT_PHYS_STATE, attr.phys_state))
 		return -EMSGSIZE;
-	return 0;
+
+	if (device->get_netdev)
+		netdev = device->get_netdev(device, port);
+
+	if (netdev && net_eq(dev_net(netdev), net)) {
+		ret = nla_put_u32(msg,
+				  RDMA_NLDEV_ATTR_NDEV_INDEX, netdev->ifindex);
+		if (ret)
+			goto out;
+		ret = nla_put_string(msg,
+				     RDMA_NLDEV_ATTR_NDEV_NAME, netdev->name);
+	}
+
+out:
+	if (netdev)
+		dev_put(netdev);
+	return ret;
 }
 
 static int fill_res_info_entry(struct sk_buff *msg,
@@ -603,7 +624,7 @@ static int nldev_port_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 			RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
 			0, 0);
 
-	err = fill_port_info(msg, device, port);
+	err = fill_port_info(msg, device, port, sock_net(skb->sk));
 	if (err)
 		goto err_free;
 
@@ -663,7 +684,7 @@ static int nldev_port_get_dumpit(struct sk_buff *skb,
 						 RDMA_NLDEV_CMD_PORT_GET),
 				0, NLM_F_MULTI);
 
-		if (fill_port_info(skb, device, p)) {
+		if (fill_port_info(skb, device, p, sock_net(skb->sk))) {
 			nlmsg_cancel(skb, nlh);
 			goto out;
 		}

include/uapi/rdma/rdma_netlink.h

@@ -388,6 +388,19 @@ enum rdma_nldev_attr {
 	RDMA_NLDEV_ATTR_RES_LOCAL_DMA_LKEY,	/* u32 */
 	RDMA_NLDEV_ATTR_RES_UNSAFE_GLOBAL_RKEY,	/* u32 */
 
+	/*
+	 * Provides logical name and index of netdevice which is
+	 * connected to physical port. This information is relevant
+	 * for RoCE and iWARP.
+	 *
+	 * The netdevices which are associated with containers are
+	 * supposed to be exported together with GID table once it
+	 * will be exposed through the netlink. Because the
+	 * associated netdevices are properties of GIDs.
+	 */
+	RDMA_NLDEV_ATTR_NDEV_INDEX,		/* u32 */
+	RDMA_NLDEV_ATTR_NDEV_NAME,		/* string */
+
 	RDMA_NLDEV_ATTR_MAX
 };
 #endif /* _UAPI_RDMA_NETLINK_H */