Merge branch 'ethtool-rssh-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bwh/net-next

Ben Hutchings says:

====================
Pull request: Fixes for new ethtool RSS commands

This addresses several problems I previously identified with the new
ETHTOOL_{G,S}RSSH commands:

1. Missing validation of reserved parameters
2. Vague documentation
3. Use of unnamed magic number
4. No consolidation with existing driver operations

I don't currently have access to suitable network hardware, but have
tested these changes with a dummy driver that can support various
combinations of operations and sizes, together with (a) Debian's ethtool
3.13 (b) ethtool 3.14 with the submitted patch to use ETHTOOL_{G,S}RSSH
and minor adjustment for fixes 1 and 3.

v2: Update RSS operations in vmxnet3 too
====================

Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c

···
 	return T_ETH_INDIRECTION_TABLE_SIZE;
 }
 
-static int bnx2x_get_rxfh_indir(struct net_device *dev, u32 *indir)
+static int bnx2x_get_rxfh(struct net_device *dev, u32 *indir, u8 *key)
 {
 	struct bnx2x *bp = netdev_priv(dev);
 	u8 ind_table[T_ETH_INDIRECTION_TABLE_SIZE] = {0};
···
 	return 0;
 }
 
-static int bnx2x_set_rxfh_indir(struct net_device *dev, const u32 *indir)
+static int bnx2x_set_rxfh(struct net_device *dev, const u32 *indir,
+			  const u8 *key)
 {
 	struct bnx2x *bp = netdev_priv(dev);
 	size_t i;
 
 	for (i = 0; i < T_ETH_INDIRECTION_TABLE_SIZE; i++) {
 		/*
-		 * The same as in bnx2x_get_rxfh_indir: we can't use a memcpy()
+		 * The same as in bnx2x_get_rxfh: we can't use a memcpy()
 		 * as an internal storage of an indirection table is a u8 array
 		 * while indir->ring_index points to an array of u32.
 		 *
···
 	.get_rxnfc		= bnx2x_get_rxnfc,
 	.set_rxnfc		= bnx2x_set_rxnfc,
 	.get_rxfh_indir_size	= bnx2x_get_rxfh_indir_size,
-	.get_rxfh_indir		= bnx2x_get_rxfh_indir,
-	.set_rxfh_indir		= bnx2x_set_rxfh_indir,
+	.get_rxfh		= bnx2x_get_rxfh,
+	.set_rxfh		= bnx2x_set_rxfh,
 	.get_channels		= bnx2x_get_channels,
 	.set_channels		= bnx2x_set_channels,
 	.get_module_info	= bnx2x_get_module_info,
···
 	.get_rxnfc		= bnx2x_get_rxnfc,
 	.set_rxnfc		= bnx2x_set_rxnfc,
 	.get_rxfh_indir_size	= bnx2x_get_rxfh_indir_size,
-	.get_rxfh_indir		= bnx2x_get_rxfh_indir,
-	.set_rxfh_indir		= bnx2x_set_rxfh_indir,
+	.get_rxfh		= bnx2x_get_rxfh,
+	.set_rxfh		= bnx2x_set_rxfh,
 	.get_channels		= bnx2x_get_channels,
 	.set_channels		= bnx2x_set_channels,
 };

drivers/net/ethernet/broadcom/tg3.c

···
 	return size;
 }
 
-static int tg3_get_rxfh_indir(struct net_device *dev, u32 *indir)
+static int tg3_get_rxfh(struct net_device *dev, u32 *indir, u8 *key)
 {
 	struct tg3 *tp = netdev_priv(dev);
 	int i;
···
 	return 0;
 }
 
-static int tg3_set_rxfh_indir(struct net_device *dev, const u32 *indir)
+static int tg3_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key)
 {
 	struct tg3 *tp = netdev_priv(dev);
 	size_t i;
···
 	.get_sset_count		= tg3_get_sset_count,
 	.get_rxnfc		= tg3_get_rxnfc,
 	.get_rxfh_indir_size    = tg3_get_rxfh_indir_size,
-	.get_rxfh_indir		= tg3_get_rxfh_indir,
-	.set_rxfh_indir		= tg3_set_rxfh_indir,
+	.get_rxfh		= tg3_get_rxfh,
+	.set_rxfh		= tg3_set_rxfh,
 	.get_channels		= tg3_get_channels,
 	.set_channels		= tg3_set_channels,
 	.get_ts_info		= tg3_get_ts_info,

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c

···
 	return pi->rss_size;
 }
 
-static int get_rss_table(struct net_device *dev, u32 *p)
+static int get_rss_table(struct net_device *dev, u32 *p, u8 *key)
 {
 	const struct port_info *pi = netdev_priv(dev);
 	unsigned int n = pi->rss_size;
···
 	return 0;
 }
 
-static int set_rss_table(struct net_device *dev, const u32 *p)
+static int set_rss_table(struct net_device *dev, const u32 *p, const u8 *key)
 {
 	unsigned int i;
 	struct port_info *pi = netdev_priv(dev);
···
 	.set_wol           = set_wol,
 	.get_rxnfc         = get_rxnfc,
 	.get_rxfh_indir_size = get_rss_table_size,
-	.get_rxfh_indir    = get_rss_table,
-	.set_rxfh_indir    = set_rss_table,
+	.get_rxfh	   = get_rss_table,
+	.set_rxfh	   = set_rss_table,
 	.flash_device      = set_flash,
 };
 

drivers/net/ethernet/emulex/benet/be_cmds.c

···
 }
 
 int be_cmd_rss_config(struct be_adapter *adapter, u8 *rsstable,
-		      u32 rss_hash_opts, u16 table_size, u8 *rss_hkey)
+		      u32 rss_hash_opts, u16 table_size, const u8 *rss_hkey)
 {
 	struct be_mcc_wrb *wrb;
 	struct be_cmd_req_rss_config *req;

drivers/net/ethernet/emulex/benet/be_cmds.h

···
 			u32 *function_mode, u32 *function_caps, u16 *asic_rev);
 int be_cmd_reset_function(struct be_adapter *adapter);
 int be_cmd_rss_config(struct be_adapter *adapter, u8 *rsstable,
-		      u32 rss_hash_opts, u16 table_size, u8 *rss_hkey);
+		      u32 rss_hash_opts, u16 table_size, const u8 *rss_hkey);
 int be_process_mcc(struct be_adapter *adapter);
 int be_cmd_set_beacon_state(struct be_adapter *adapter, u8 port_num, u8 beacon,
 			    u8 status, u8 state);

drivers/net/ethernet/emulex/benet/be_ethtool.c

···
 	return 0;
 }
 
-static int be_set_rxfh(struct net_device *netdev, u32 *indir, u8 *hkey)
+static int be_set_rxfh(struct net_device *netdev, const u32 *indir,
+		       const u8 *hkey)
 {
 	int rc = 0, i, j;
 	struct be_adapter *adapter = netdev_priv(netdev);

drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c

···
 }
 
 /**
- * i40evf_get_rxfh_indir - get the rx flow hash indirection table
+ * i40evf_get_rxfh - get the rx flow hash indirection table
  * @netdev: network interface device structure
  * @indir: indirection table
+ * @key: hash key (will be %NULL until get_rxfh_key_size is implemented)
  *
  * Reads the indirection table directly from the hardware. Always returns 0.
  **/
-static int i40evf_get_rxfh_indir(struct net_device *netdev, u32 *indir)
+static int i40evf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key)
 {
 	struct i40evf_adapter *adapter = netdev_priv(netdev);
 	struct i40e_hw *hw = &adapter->hw;
···
 }
 
 /**
- * i40evf_set_rxfh_indir - set the rx flow hash indirection table
+ * i40evf_set_rxfh - set the rx flow hash indirection table
  * @netdev: network interface device structure
  * @indir: indirection table
+ * @key: hash key (will be %NULL until get_rxfh_key_size is implemented)
  *
  * Returns -EINVAL if the table specifies an inavlid queue id, otherwise
  * returns 0 after programming the table.
  **/
-static int i40evf_set_rxfh_indir(struct net_device *netdev, const u32 *indir)
+static int i40evf_set_rxfh(struct net_device *netdev, const u32 *indir,
+			   const u8 *key)
 {
 	struct i40evf_adapter *adapter = netdev_priv(netdev);
 	struct i40e_hw *hw = &adapter->hw;
···
 	.get_rxnfc		= i40evf_get_rxnfc,
 	.set_rxnfc		= i40evf_set_rxnfc,
 	.get_rxfh_indir_size	= i40evf_get_rxfh_indir_size,
-	.get_rxfh_indir		= i40evf_get_rxfh_indir,
-	.set_rxfh_indir		= i40evf_set_rxfh_indir,
+	.get_rxfh		= i40evf_get_rxfh,
+	.set_rxfh		= i40evf_set_rxfh,
 	.get_channels		= i40evf_get_channels,
 };
 

drivers/net/ethernet/intel/igb/igb_ethtool.c

···
 	return IGB_RETA_SIZE;
 }
 
-static int igb_get_rxfh_indir(struct net_device *netdev, u32 *indir)
+static int igb_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key)
 {
 	struct igb_adapter *adapter = netdev_priv(netdev);
 	int i;
···
 	}
 }
 
-static int igb_set_rxfh_indir(struct net_device *netdev, const u32 *indir)
+static int igb_set_rxfh(struct net_device *netdev, const u32 *indir,
+			const u8 *key)
 {
 	struct igb_adapter *adapter = netdev_priv(netdev);
 	struct e1000_hw *hw = &adapter->hw;
···
 	.get_module_info	= igb_get_module_info,
 	.get_module_eeprom	= igb_get_module_eeprom,
 	.get_rxfh_indir_size	= igb_get_rxfh_indir_size,
-	.get_rxfh_indir		= igb_get_rxfh_indir,
-	.set_rxfh_indir		= igb_set_rxfh_indir,
+	.get_rxfh		= igb_get_rxfh,
+	.set_rxfh		= igb_set_rxfh,
 	.get_channels		= igb_get_channels,
 	.set_channels		= igb_set_channels,
 	.begin			= igb_ethtool_begin,

drivers/net/ethernet/mellanox/mlx4/en_ethtool.c

···
 	return priv->rx_ring_num;
 }
 
-static int mlx4_en_get_rxfh_indir(struct net_device *dev, u32 *ring_index)
+static int mlx4_en_get_rxfh(struct net_device *dev, u32 *ring_index, u8 *key)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
 	struct mlx4_en_rss_map *rss_map = &priv->rss_map;
···
 	return err;
 }
 
-static int mlx4_en_set_rxfh_indir(struct net_device *dev,
-		const u32 *ring_index)
+static int mlx4_en_set_rxfh(struct net_device *dev, const u32 *ring_index,
+			    const u8 *key)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
 	struct mlx4_en_dev *mdev = priv->mdev;
···
 	.get_rxnfc = mlx4_en_get_rxnfc,
 	.set_rxnfc = mlx4_en_set_rxnfc,
 	.get_rxfh_indir_size = mlx4_en_get_rxfh_indir_size,
-	.get_rxfh_indir = mlx4_en_get_rxfh_indir,
-	.set_rxfh_indir = mlx4_en_set_rxfh_indir,
+	.get_rxfh = mlx4_en_get_rxfh,
+	.set_rxfh = mlx4_en_set_rxfh,
 	.get_channels = mlx4_en_get_channels,
 	.set_channels = mlx4_en_set_channels,
 	.get_ts_info = mlx4_en_get_ts_info,

drivers/net/ethernet/sfc/ethtool.c

···
 		0 : ARRAY_SIZE(efx->rx_indir_table));
 }
 
-static int efx_ethtool_get_rxfh_indir(struct net_device *net_dev, u32 *indir)
+static int efx_ethtool_get_rxfh(struct net_device *net_dev, u32 *indir, u8 *key)
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
 
···
 	return 0;
 }
 
-static int efx_ethtool_set_rxfh_indir(struct net_device *net_dev,
-				      const u32 *indir)
+static int efx_ethtool_set_rxfh(struct net_device *net_dev,
+				const u32 *indir, const u8 *key)
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
 
···
 	.get_rxnfc		= efx_ethtool_get_rxnfc,
 	.set_rxnfc		= efx_ethtool_set_rxnfc,
 	.get_rxfh_indir_size	= efx_ethtool_get_rxfh_indir_size,
-	.get_rxfh_indir		= efx_ethtool_get_rxfh_indir,
-	.set_rxfh_indir		= efx_ethtool_set_rxfh_indir,
+	.get_rxfh		= efx_ethtool_get_rxfh,
+	.set_rxfh		= efx_ethtool_set_rxfh,
 	.get_ts_info		= efx_ethtool_get_ts_info,
 	.get_module_info	= efx_ethtool_get_module_info,
 	.get_module_eeprom	= efx_ethtool_get_module_eeprom,

drivers/net/vmxnet3/vmxnet3_ethtool.c

···
 }
 
 static int
-vmxnet3_get_rss_indir(struct net_device *netdev, u32 *p)
+vmxnet3_get_rss(struct net_device *netdev, u32 *p, u8 *key)
 {
 	struct vmxnet3_adapter *adapter = netdev_priv(netdev);
 	struct UPT1_RSSConf *rssConf = adapter->rss_conf;
···
 }
 
 static int
-vmxnet3_set_rss_indir(struct net_device *netdev, const u32 *p)
+vmxnet3_set_rss(struct net_device *netdev, const u32 *p, const u8 *key)
 {
 	unsigned int i;
 	unsigned long flags;
···
 	.get_rxnfc         = vmxnet3_get_rxnfc,
 #ifdef VMXNET3_RSS
 	.get_rxfh_indir_size = vmxnet3_get_rss_indir_size,
-	.get_rxfh_indir    = vmxnet3_get_rss_indir,
-	.set_rxfh_indir    = vmxnet3_set_rss_indir,
+	.get_rxfh          = vmxnet3_get_rss,
+	.set_rxfh          = vmxnet3_set_rss,
 #endif
 };
 

include/linux/ethtool.h

···
  *	Returns zero if not supported for this specific device.
  * @get_rxfh_indir_size: Get the size of the RX flow hash indirection table.
  *	Returns zero if not supported for this specific device.
- * @get_rxfh_indir: Get the contents of the RX flow hash indirection table.
- *	Will not be called if @get_rxfh_indir_size returns zero.
  * @get_rxfh: Get the contents of the RX flow hash indirection table and hash
  *	key.
- *	Will not be called if @get_rxfh_indir_size and @get_rxfh_key_size
- *	returns zero.
+ *	Will only be called if one or both of @get_rxfh_indir_size and
+ *	@get_rxfh_key_size are implemented and return non-zero.
  *	Returns a negative error code or zero.
- * @set_rxfh_indir: Set the contents of the RX flow hash indirection table.
- *	Will not be called if @get_rxfh_indir_size returns zero.
- * @set_rxfh: Set the contents of the RX flow hash indirection table and
- *	hash key.
- *	Will not be called if @get_rxfh_indir_size and @get_rxfh_key_size
- *	returns zero.
+ * @set_rxfh: Set the contents of the RX flow hash indirection table and/or
+ *	hash key.  In case only the indirection table or hash key is to be
+ *	changed, the other argument will be %NULL.
+ *	Will only be called if one or both of @get_rxfh_indir_size and
+ *	@get_rxfh_key_size are implemented and return non-zero.
  *	Returns a negative error code or zero.
  * @get_channels: Get number of channels.
  * @set_channels: Set number of channels.  Returns a negative error code or
···
 	int	(*reset)(struct net_device *, u32 *);
 	u32	(*get_rxfh_key_size)(struct net_device *);
 	u32	(*get_rxfh_indir_size)(struct net_device *);
-	int	(*get_rxfh)(struct net_device *, u32 *, u8 *);
-	int	(*set_rxfh)(struct net_device *, u32 *, u8 *);
-	int	(*get_rxfh_indir)(struct net_device *, u32 *);
-	int	(*set_rxfh_indir)(struct net_device *, const u32 *);
+	int	(*get_rxfh)(struct net_device *, u32 *indir, u8 *key);
+	int	(*set_rxfh)(struct net_device *, const u32 *indir,
+			    const u8 *key);
 	void	(*get_channels)(struct net_device *, struct ethtool_channels *);
 	int	(*set_channels)(struct net_device *, struct ethtool_channels *);
 	int	(*get_dump_flag)(struct net_device *, struct ethtool_dump *);

include/uapi/linux/ethtool.h

···
  * struct ethtool_rxfh - command to get/set RX flow hash indir or/and hash key.
  * @cmd: Specific command number - %ETHTOOL_GRSSH or %ETHTOOL_SRSSH
  * @rss_context: RSS context identifier.
- * @indir_size: On entry, the array size of the user buffer, which may be zero.
- *		On return from %ETHTOOL_GRSSH, the array size of the hardware
- *		indirection table.
- * @key_size:	On entry, the array size of the user buffer in bytes,
- *		which may be zero.
- *		On return from %ETHTOOL_GRSSH, the size of the RSS hash key.
+ * @indir_size: On entry, the array size of the user buffer for the
+ *	indirection table, which may be zero, or (for %ETHTOOL_SRSSH),
+ *	%ETH_RXFH_INDIR_NO_CHANGE.  On return from %ETHTOOL_GRSSH,
+ *	the array size of the hardware indirection table.
+ * @key_size: On entry, the array size of the user buffer for the hash key,
+ *	which may be zero.  On return from %ETHTOOL_GRSSH, the size of the
+ *	hardware hash key.
  * @rsvd:	Reserved for future extensions.
  * @rss_config: RX ring/queue index for each hash value i.e., indirection table
- *		of size @indir_size followed by hash key of size @key_size.
+ *	of @indir_size __u32 elements, followed by hash key of @key_size
+ *	bytes.
  *
  * For %ETHTOOL_GRSSH, a @indir_size and key_size of zero means that only the
- * size should be returned.  For %ETHTOOL_SRSSH, a @indir_size of 0xDEADBEEF
- * means that indir table setting is not requested and a @indir_size of zero
- * means the indir table should be reset to default values.  This last feature
- * is not supported by the original implementations.
+ * size should be returned.  For %ETHTOOL_SRSSH, an @indir_size of
+ * %ETH_RXFH_INDIR_NO_CHANGE means that indir table setting is not requested
+ * and a @indir_size of zero means the indir table should be reset to default
+ * values.
  */
 struct ethtool_rxfh {
 	__u32   cmd;
···
 	__u32	rsvd[2];
 	__u32   rss_config[0];
 };
+#define ETH_RXFH_INDIR_NO_CHANGE	0xffffffff
 
 /**
  * struct ethtool_rx_ntuple_flow_spec - specification for RX flow filter

net/core/ethtool.c

···
 					struct ethtool_rxnfc *rx_rings,
 					u32 size)
 {
-	int ret = 0, i;
+	int i;
 
 	if (copy_from_user(indir, useraddr, size * sizeof(indir[0])))
-		ret = -EFAULT;
+		return -EFAULT;
 
 	/* Validate ring indices */
-	for (i = 0; i < size; i++) {
-		if (indir[i] >= rx_rings->data) {
-			ret = -EINVAL;
-			break;
-		}
-	}
-	return ret;
+	for (i = 0; i < size; i++)
+		if (indir[i] >= rx_rings->data)
+			return -EINVAL;
+
+	return 0;
 }
 
 static noinline_for_stack int ethtool_get_rxfh_indir(struct net_device *dev,
···
 	int ret;
 
 	if (!dev->ethtool_ops->get_rxfh_indir_size ||
-	    !dev->ethtool_ops->get_rxfh_indir)
+	    !dev->ethtool_ops->get_rxfh)
 		return -EOPNOTSUPP;
 	dev_size = dev->ethtool_ops->get_rxfh_indir_size(dev);
 	if (dev_size == 0)
···
 	if (!indir)
 		return -ENOMEM;
 
-	ret = dev->ethtool_ops->get_rxfh_indir(dev, indir);
+	ret = dev->ethtool_ops->get_rxfh(dev, indir, NULL);
 	if (ret)
 		goto out;
 
···
 	int ret;
 	u32 ringidx_offset = offsetof(struct ethtool_rxfh_indir, ring_index[0]);
 
-	if (!ops->get_rxfh_indir_size || !ops->set_rxfh_indir ||
+	if (!ops->get_rxfh_indir_size || !ops->set_rxfh ||
 	    !ops->get_rxnfc)
 		return -EOPNOTSUPP;
 
···
 			goto out;
 	}
 
-	ret = ops->set_rxfh_indir(dev, indir);
+	ret = ops->set_rxfh(dev, indir, NULL);
 
 out:
 	kfree(indir);
···
 {
 	int ret;
 	const struct ethtool_ops *ops = dev->ethtool_ops;
-	u32 user_indir_size = 0, user_key_size = 0;
+	u32 user_indir_size, user_key_size;
 	u32 dev_indir_size = 0, dev_key_size = 0;
+	struct ethtool_rxfh rxfh;
 	u32 total_size;
-	u32 indir_offset, indir_bytes;
-	u32 key_offset;
+	u32 indir_bytes;
 	u32 *indir = NULL;
 	u8 *hkey = NULL;
 	u8 *rss_config;
···
 
 	if (ops->get_rxfh_indir_size)
 		dev_indir_size = ops->get_rxfh_indir_size(dev);
-
-	indir_offset = offsetof(struct ethtool_rxfh, indir_size);
-
-	if (copy_from_user(&user_indir_size,
-			   useraddr + indir_offset,
-			   sizeof(user_indir_size)))
-		return -EFAULT;
-
-	if (copy_to_user(useraddr + indir_offset,
-			 &dev_indir_size, sizeof(dev_indir_size)))
-		return -EFAULT;
-
 	if (ops->get_rxfh_key_size)
 		dev_key_size = ops->get_rxfh_key_size(dev);
 
 	if ((dev_key_size + dev_indir_size) == 0)
 		return -EOPNOTSUPP;
 
-	key_offset = offsetof(struct ethtool_rxfh, key_size);
-
-	if (copy_from_user(&user_key_size,
-			   useraddr + key_offset,
-			   sizeof(user_key_size)))
+	if (copy_from_user(&rxfh, useraddr, sizeof(rxfh)))
 		return -EFAULT;
+	user_indir_size = rxfh.indir_size;
+	user_key_size = rxfh.key_size;
 
-	if (copy_to_user(useraddr + key_offset,
-			 &dev_key_size, sizeof(dev_key_size)))
+	/* Check that reserved fields are 0 for now */
+	if (rxfh.rss_context || rxfh.rsvd[0] || rxfh.rsvd[1])
+		return -EINVAL;
+
+	rxfh.indir_size = dev_indir_size;
+	rxfh.key_size = dev_key_size;
+	if (copy_to_user(useraddr, &rxfh, sizeof(rxfh)))
 		return -EFAULT;
 
 	/* If the user buffer size is 0, this is just a query for the
···
 	int ret;
 	const struct ethtool_ops *ops = dev->ethtool_ops;
 	struct ethtool_rxnfc rx_rings;
-	u32 user_indir_size = 0, dev_indir_size = 0, i;
-	u32 user_key_size = 0, dev_key_size = 0;
+	struct ethtool_rxfh rxfh;
+	u32 dev_indir_size = 0, dev_key_size = 0, i;
 	u32 *indir = NULL, indir_bytes = 0;
 	u8 *hkey = NULL;
 	u8 *rss_config;
-	u32 indir_offset, key_offset;
 	u32 rss_cfg_offset = offsetof(struct ethtool_rxfh, rss_config[0]);
 
 	if (!(ops->get_rxfh_indir_size || ops->get_rxfh_key_size) ||
···
 
 	if (ops->get_rxfh_indir_size)
 		dev_indir_size = ops->get_rxfh_indir_size(dev);
-
-	indir_offset = offsetof(struct ethtool_rxfh, indir_size);
-	if (copy_from_user(&user_indir_size,
-			   useraddr + indir_offset,
-			   sizeof(user_indir_size)))
-		return -EFAULT;
-
 	if (ops->get_rxfh_key_size)
 		dev_key_size = dev->ethtool_ops->get_rxfh_key_size(dev);
-
 	if ((dev_key_size + dev_indir_size) == 0)
 		return -EOPNOTSUPP;
 
-	key_offset = offsetof(struct ethtool_rxfh, key_size);
-	if (copy_from_user(&user_key_size,
-			   useraddr + key_offset,
-			   sizeof(user_key_size)))
+	if (copy_from_user(&rxfh, useraddr, sizeof(rxfh)))
 		return -EFAULT;
 
-	/* If either indir or hash key is valid, proceed further.
-	 */
-	if ((user_indir_size && ((user_indir_size != 0xDEADBEEF) &&
-				 user_indir_size != dev_indir_size)) ||
-	    (user_key_size && (user_key_size != dev_key_size)))
+	/* Check that reserved fields are 0 for now */
+	if (rxfh.rss_context || rxfh.rsvd[0] || rxfh.rsvd[1])
 		return -EINVAL;
 
-	if (user_indir_size != 0xDEADBEEF)
+	/* If either indir or hash key is valid, proceed further.
+	 * It is not valid to request that both be unchanged.
+	 */
+	if ((rxfh.indir_size &&
+	     rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE &&
+	     rxfh.indir_size != dev_indir_size) ||
+	    (rxfh.key_size && (rxfh.key_size != dev_key_size)) ||
+	    (rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE &&
+	     rxfh.key_size == 0))
+		return -EINVAL;
+
+	if (rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE)
 		indir_bytes = dev_indir_size * sizeof(indir[0]);
 
-	rss_config = kzalloc(indir_bytes + user_key_size, GFP_USER);
+	rss_config = kzalloc(indir_bytes + rxfh.key_size, GFP_USER);
 	if (!rss_config)
 		return -ENOMEM;
 
···
 	if (ret)
 		goto out;
 
-	/* user_indir_size == 0 means reset the indir table to default.
-	 * user_indir_size == 0xDEADBEEF means indir setting is not requested.
+	/* rxfh.indir_size == 0 means reset the indir table to default.
+	 * rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE means leave it unchanged.
 	 */
-	if (user_indir_size && user_indir_size != 0xDEADBEEF) {
+	if (rxfh.indir_size &&
+	    rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE) {
 		indir = (u32 *)rss_config;
 		ret = ethtool_copy_validate_indir(indir,
 						  useraddr + rss_cfg_offset,
 						  &rx_rings,
-						  user_indir_size);
+						  rxfh.indir_size);
 		if (ret)
 			goto out;
-	} else if (user_indir_size == 0) {
+	} else if (rxfh.indir_size == 0) {
 		indir = (u32 *)rss_config;
 		for (i = 0; i < dev_indir_size; i++)
 			indir[i] = ethtool_rxfh_indir_default(i, rx_rings.data);
 	}
 
-	if (user_key_size) {
+	if (rxfh.key_size) {
 		hkey = rss_config + indir_bytes;
 		if (copy_from_user(hkey,
 				   useraddr + rss_cfg_offset + indir_bytes,
-				   user_key_size)) {
+				   rxfh.key_size)) {
 			ret = -EFAULT;
 			goto out;
 		}