net: ethtool: copy the rxfh flow handling

RX Flow Hash configuration uses the same argument structure
as flow filters. This is probably why ethtool IOCTL handles
them together. The more checks we add the more convoluted
this code is getting (as some of the checks apply only
to flow filters and others only to the hashing).

Copy the code to separate the handling. This is an exact
copy, the next change will remove unnecessary handling.

Reviewed-by: Joe Damato <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

net/ethtool/ioctl.c

@@ -1060,6 +1060,93 @@ static int ethtool_check_flow_types(struct net_device *dev, u32 input_xfrm)
 	return 0;
 }
 
+static noinline_for_stack int
+ethtool_set_rxfh_fields(struct net_device *dev, u32 cmd, void __user *useraddr)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_rxnfc info;
+	size_t info_size = sizeof(info);
+	int rc;
+
+	if (!ops->set_rxnfc)
+		return -EOPNOTSUPP;
+
+	rc = ethtool_rxnfc_copy_struct(cmd, &info, &info_size, useraddr);
+	if (rc)
+		return rc;
+
+	if (cmd == ETHTOOL_SRXCLSRLINS && info.fs.flow_type & FLOW_RSS) {
+		/* Nonzero ring with RSS only makes sense
+		 * if NIC adds them together
+		 */
+		if (!ops->cap_rss_rxnfc_adds &&
+		    ethtool_get_flow_spec_ring(info.fs.ring_cookie))
+			return -EINVAL;
+
+		if (!xa_load(&dev->ethtool->rss_ctx, info.rss_context))
+			return -EINVAL;
+	}
+
+	if (cmd == ETHTOOL_SRXFH && ops->get_rxfh) {
+		struct ethtool_rxfh_param rxfh = {};
+
+		rc = ops->get_rxfh(dev, &rxfh);
+		if (rc)
+			return rc;
+
+		rc = ethtool_check_xfrm_rxfh(rxfh.input_xfrm, info.data);
+		if (rc)
+			return rc;
+	}
+
+	rc = ops->set_rxnfc(dev, &info);
+	if (rc)
+		return rc;
+
+	if (cmd == ETHTOOL_SRXCLSRLINS &&
+	    ethtool_rxnfc_copy_to_user(useraddr, &info, info_size, NULL))
+		return -EFAULT;
+
+	return 0;
+}
+
+static noinline_for_stack int
+ethtool_get_rxfh_fields(struct net_device *dev, u32 cmd, void __user *useraddr)
+{
+	struct ethtool_rxnfc info;
+	size_t info_size = sizeof(info);
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	int ret;
+	void *rule_buf = NULL;
+
+	if (!ops->get_rxnfc)
+		return -EOPNOTSUPP;
+
+	ret = ethtool_rxnfc_copy_struct(cmd, &info, &info_size, useraddr);
+	if (ret)
+		return ret;
+
+	if (info.cmd == ETHTOOL_GRXCLSRLALL) {
+		if (info.rule_cnt > 0) {
+			if (info.rule_cnt <= KMALLOC_MAX_SIZE / sizeof(u32))
+				rule_buf = kcalloc(info.rule_cnt, sizeof(u32),
+						   GFP_USER);
+			if (!rule_buf)
+				return -ENOMEM;
+		}
+	}
+
+	ret = ops->get_rxnfc(dev, &info, rule_buf);
+	if (ret < 0)
+		goto err_out;
+
+	ret = ethtool_rxnfc_copy_to_user(useraddr, &info, info_size, rule_buf);
+err_out:
+	kfree(rule_buf);
+
+	return ret;
+}
+
 static noinline_for_stack int ethtool_set_rxnfc(struct net_device *dev,
 						u32 cmd, void __user *useraddr)
 {
@@ -3339,13 +3426,17 @@ __dev_ethtool(struct net *net, struct ifreq *ifr, void __user *useraddr,
 				       dev->ethtool_ops->set_priv_flags);
 		break;
 	case ETHTOOL_GRXFH:
+		rc = ethtool_get_rxfh_fields(dev, ethcmd, useraddr);
+		break;
+	case ETHTOOL_SRXFH:
+		rc = ethtool_set_rxfh_fields(dev, ethcmd, useraddr);
+		break;
 	case ETHTOOL_GRXRINGS:
 	case ETHTOOL_GRXCLSRLCNT:
 	case ETHTOOL_GRXCLSRULE:
 	case ETHTOOL_GRXCLSRLALL:
 		rc = ethtool_get_rxnfc(dev, ethcmd, useraddr);
 		break;
-	case ETHTOOL_SRXFH:
 	case ETHTOOL_SRXCLSRLDEL:
 	case ETHTOOL_SRXCLSRLINS:
 		rc = ethtool_set_rxnfc(dev, ethcmd, useraddr);