RDMA/nldev: Allow IB device rename through RDMA netlink

Provide an option to rename IB device name through RDMA netlink and
limit it to users with ADMIN capability only.
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/nldev.c

@@ -646,6 +646,36 @@ static int nldev_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 	return err;
 }
 
+static int nldev_set_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
+			  struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
+	struct ib_device *device;
+	u32 index;
+	int err;
+
+	err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1, nldev_policy,
+			  extack);
+	if (err || !tb[RDMA_NLDEV_ATTR_DEV_INDEX])
+		return -EINVAL;
+
+	index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
+	device = ib_device_get_by_index(index);
+	if (!device)
+		return -EINVAL;
+
+	if (tb[RDMA_NLDEV_ATTR_DEV_NAME]) {
+		char name[IB_DEVICE_NAME_MAX] = {};
+
+		nla_strlcpy(name, tb[RDMA_NLDEV_ATTR_DEV_NAME],
+			    IB_DEVICE_NAME_MAX);
+		err = ib_device_rename(device, name);
+	}
+
+	put_device(&device->dev);
+	return err;
+}
+
 static int _nldev_get_dumpit(struct ib_device *device,
 			     struct sk_buff *skb,
 			     struct netlink_callback *cb,
@@ -1078,6 +1108,10 @@ static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
 		.doit = nldev_get_doit,
 		.dump = nldev_get_dumpit,
 	},
+	[RDMA_NLDEV_CMD_SET] = {
+		.doit = nldev_set_doit,
+		.flags = RDMA_NL_ADMIN_PERM,
+	},
 	[RDMA_NLDEV_CMD_PORT_GET] = {
 		.doit = nldev_port_get_doit,
 		.dump = nldev_port_get_dumpit,

include/uapi/rdma/rdma_netlink.h

@@ -227,8 +227,9 @@ enum rdma_nldev_command {
 	RDMA_NLDEV_CMD_UNSPEC,
 
 	RDMA_NLDEV_CMD_GET, /* can dump */
+	RDMA_NLDEV_CMD_SET,
 
-	/* 2 - 4 are free to use */
+	/* 3 - 4 are free to use */
 
 	RDMA_NLDEV_CMD_PORT_GET = 5, /* can dump */