ethtool, ixgbe: Move RX n-tuple mask fixup to ethtool

The ethtool utility does not set masks for flow parameters that are
not specified, so if both value and mask are 0 then this must be
treated as equivalent to a mask with all bits set.  Currently that is
done in the only driver that implements RX n-tuple filtering, ixgbe.
Move it to the ethtool core.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 248c25c..91ffce2 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -485,6 +485,38 @@
 	list->count++;
 }
 
+/*
+ * ethtool does not (or did not) set masks for flow parameters that are
+ * not specified, so if both value and mask are 0 then this must be
+ * treated as equivalent to a mask with all bits set.  Implement that
+ * here rather than in drivers.
+ */
+static void rx_ntuple_fix_masks(struct ethtool_rx_ntuple_flow_spec *fs)
+{
+	struct ethtool_tcpip4_spec *entry = &fs->h_u.tcp_ip4_spec;
+	struct ethtool_tcpip4_spec *mask = &fs->m_u.tcp_ip4_spec;
+
+	if (fs->flow_type != TCP_V4_FLOW &&
+	    fs->flow_type != UDP_V4_FLOW &&
+	    fs->flow_type != SCTP_V4_FLOW)
+		return;
+
+	if (!(entry->ip4src | mask->ip4src))
+		mask->ip4src = htonl(0xffffffff);
+	if (!(entry->ip4dst | mask->ip4dst))
+		mask->ip4dst = htonl(0xffffffff);
+	if (!(entry->psrc | mask->psrc))
+		mask->psrc = htons(0xffff);
+	if (!(entry->pdst | mask->pdst))
+		mask->pdst = htons(0xffff);
+	if (!(entry->tos | mask->tos))
+		mask->tos = 0xff;
+	if (!(fs->vlan_tag | fs->vlan_tag_mask))
+		fs->vlan_tag_mask = 0xffff;
+	if (!(fs->data | fs->data_mask))
+		fs->data_mask = 0xffffffffffffffffULL;
+}
+
 static noinline_for_stack int ethtool_set_rx_ntuple(struct net_device *dev,
 						    void __user *useraddr)
 {
@@ -499,6 +531,8 @@
 	if (copy_from_user(&cmd, useraddr, sizeof(cmd)))
 		return -EFAULT;
 
+	rx_ntuple_fix_masks(&cmd.fs);
+
 	/*
 	 * Cache filter in dev struct for GET operation only if
 	 * the underlying driver doesn't have its own GET operation, and