[PATCH rdma-next v3 05/14] RDMA/nldev: Allow setting the device name while changing net namespace

From: Jiri Pirko <[email protected]>

Accept RDMA_NLDEV_ATTR_DEV_NAME together with RDMA_NLDEV_NET_NS_FD so a
netlink move can rename the device in the destination namespace. Keep the
name semantics aligned with the existing RDMA rename path.

Signed-off-by: Jiri Pirko <[email protected]>
---
 drivers/infiniband/core/device.c |  6 ++++++
 drivers/infiniband/core/nldev.c  | 27 ++++++++++++++++++---------
 include/uapi/rdma/rdma_netlink.h |  5 ++++-
 3 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 366bd8463c07..bb02640239d7 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -1901,6 +1901,9 @@ int ib_device_set_netns_put(struct sk_buff *skb,
 		if (ret == -EEXIST)
 			NL_SET_ERR_MSG(extack,
 				       "Device name already exists in the target net namespace");
+		else if (ret == -EINVAL && name)
+			NL_SET_ERR_MSG(extack,
+				       "Unable to use requested device name in the target net namespace");
 		goto ns_err;
 	}
 
@@ -1931,6 +1934,9 @@ int ib_device_set_netns_put(struct sk_buff *skb,
 	if (ret == -EEXIST)
 		NL_SET_ERR_MSG(extack,
 			       "Device name already exists in the target net namespace");
+	else if (ret == -EINVAL && name)
+		NL_SET_ERR_MSG(extack,
+			       "Unable to use requested device name in the target net namespace");
 
 	put_net(net);
 	return ret;
diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 8648e95700bf..4efa387ec1be 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -1178,6 +1178,24 @@ static int nldev_set_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (!device)
 		return -EINVAL;
 
+	if (tb[RDMA_NLDEV_NET_NS_FD]) {
+		char name[IB_DEVICE_NAME_MAX] = {};
+		u32 ns_fd;
+
+		if (tb[RDMA_NLDEV_ATTR_DEV_NAME]) {
+			nla_strscpy(name, tb[RDMA_NLDEV_ATTR_DEV_NAME],
+				    IB_DEVICE_NAME_MAX);
+			if (strlen(name) == 0) {
+				err = -EINVAL;
+				goto done;
+			}
+		}
+		ns_fd = nla_get_u32(tb[RDMA_NLDEV_NET_NS_FD]);
+		err = ib_device_set_netns_put(skb, device, ns_fd,
+					      name[0] ? name : NULL, extack);
+		goto put_done;
+	}
+
 	if (tb[RDMA_NLDEV_ATTR_DEV_NAME]) {
 		char name[IB_DEVICE_NAME_MAX] = {};
 
@@ -1191,15 +1209,6 @@ static int nldev_set_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 		goto done;
 	}
 
-	if (tb[RDMA_NLDEV_NET_NS_FD]) {
-		u32 ns_fd;
-
-		ns_fd = nla_get_u32(tb[RDMA_NLDEV_NET_NS_FD]);
-		err = ib_device_set_netns_put(skb, device, ns_fd, NULL,
-					      extack);
-		goto put_done;
-	}
-
 	if (tb[RDMA_NLDEV_ATTR_DEV_DIM]) {
 		u8 use_dim;
 
diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
index 3af946ecbac3..ee11c3bbbae2 100644
--- a/include/uapi/rdma/rdma_netlink.h
+++ b/include/uapi/rdma/rdma_netlink.h
@@ -516,7 +516,10 @@ enum rdma_nldev_attr {
 	RDMA_NLDEV_ATTR_DEV_PROTOCOL,		/* string */
 
 	/*
-	 * File descriptor handle of the net namespace object
+	 * File descriptor handle of the net namespace object. May be combined
+	 * with RDMA_NLDEV_ATTR_DEV_NAME (a literal device name) to also rename
+	 * the device in the destination namespace; the move fails with -EEXIST
+	 * if that name is already taken there.
 	 */
 	RDMA_NLDEV_NET_NS_FD,			/* u32 */
 	/*
-- 
2.54.0