net: ethtool: Allow PHY cable test TDR data to configured

Allow the user to configure where on the cable the TDR data should be
retrieved, in terms of first and last sample, and the step between
samples. Also add the ability to ask for TDR data for just one pair.

If this configuration is not provided, it defaults to 1-150m at 1m
intervals for all pairs.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>

v3:
Move the TDR configuration into a structure
Add a range check on step
Use NL_SET_ERR_MSG_ATTR() when appropriate
Move TDR configuration into a nest
Document attributes in the request

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 102 insertions, 2 deletions

diff --git a/net/ethtool/cabletest.c b/net/ethtool/cabletest.c
index 390d0673ff01..9991688d7d1d 100644
--- a/net/ethtool/cabletest.c
+++ b/net/ethtool/cabletest.c
@@ -5,7 +5,11 @@
 #include "netlink.h"
 #include "common.h"
 
-/* CABLE_TEST_ACT */
+/* 802.3 standard allows 100 meters for BaseT cables. However longer
+ * cables might work, depending on the quality of the cables and the
+ * PHY. So allow testing for up to 150 meters.
+ */
+#define MAX_CABLE_LENGTH_CM (150 * 100)
 
 static const struct nla_policy
 cable_test_act_policy[ETHTOOL_A_CABLE_TEST_MAX + 1] = {
@@ -203,16 +207,107 @@ err:
 }
 EXPORT_SYMBOL_GPL(ethnl_cable_test_fault_length);
 
+struct cable_test_tdr_req_info {
+	struct ethnl_req_info		base;
+};
+
+static const struct nla_policy
+cable_test_tdr_act_cfg_policy[ETHTOOL_A_CABLE_TEST_TDR_CFG_MAX + 1] = {
+	[ETHTOOL_A_CABLE_TEST_TDR_CFG_FIRST]	= { .type = NLA_U32 },
+	[ETHTOOL_A_CABLE_TEST_TDR_CFG_LAST]	= { .type = NLA_U32 },
+	[ETHTOOL_A_CABLE_TEST_TDR_CFG_STEP]	= { .type = NLA_U32 },
+	[ETHTOOL_A_CABLE_TEST_TDR_CFG_PAIR]	= { .type = NLA_U8 },
+};
+
 static const struct nla_policy
 cable_test_tdr_act_policy[ETHTOOL_A_CABLE_TEST_TDR_MAX + 1] = {
 	[ETHTOOL_A_CABLE_TEST_TDR_UNSPEC]	= { .type = NLA_REJECT },
 	[ETHTOOL_A_CABLE_TEST_TDR_HEADER]	= { .type = NLA_NESTED },
+	[ETHTOOL_A_CABLE_TEST_TDR_CFG]		= { .type = NLA_NESTED },
 };
 
+/* CABLE_TEST_TDR_ACT */
+int ethnl_act_cable_test_tdr_cfg(const struct nlattr *nest,
+				 struct genl_info *info,
+				 struct phy_tdr_config *cfg)
+{
+	struct nlattr *tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_MAX + 1];
+	int ret;
+
+	ret = nla_parse_nested(tb, ETHTOOL_A_CABLE_TEST_TDR_CFG_MAX, nest,
+			       cable_test_tdr_act_cfg_policy, info->extack);
+	if (ret < 0)
+		return ret;
+
+	if (tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_FIRST])
+		cfg->first = nla_get_u32(
+			tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_FIRST]);
+	else
+		cfg->first = 100;
+	if (tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_LAST])
+		cfg->last = nla_get_u32(tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_LAST]);
+	else
+		cfg->last = MAX_CABLE_LENGTH_CM;
+
+	if (tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_STEP])
+		cfg->step = nla_get_u32(tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_STEP]);
+	else
+		cfg->step = 100;
+
+	if (tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_PAIR]) {
+		cfg->pair = nla_get_u8(tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_PAIR]);
+		if (cfg->pair > ETHTOOL_A_CABLE_PAIR_D) {
+			NL_SET_ERR_MSG_ATTR(
+				info->extack,
+				tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_PAIR],
+				"invalid pair parameter");
+			return -EINVAL;
+		}
+	} else {
+		cfg->pair = PHY_PAIR_ALL;
+	}
+
+	if (cfg->first > MAX_CABLE_LENGTH_CM) {
+		NL_SET_ERR_MSG_ATTR(info->extack,
+				    tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_FIRST],
+				    "invalid first parameter");
+		return -EINVAL;
+	}
+
+	if (cfg->last > MAX_CABLE_LENGTH_CM) {
+		NL_SET_ERR_MSG_ATTR(info->extack,
+				    tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_LAST],
+				    "invalid last parameter");
+		return -EINVAL;
+	}
+
+	if (cfg->first > cfg->last) {
+		NL_SET_ERR_MSG(info->extack, "invalid first/last parameter");
+		return -EINVAL;
+	}
+
+	if (!cfg->step) {
+		NL_SET_ERR_MSG_ATTR(info->extack,
+				    tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_STEP],
+				    "invalid step parameter");
+		return -EINVAL;
+	}
+
+	if (cfg->step > (cfg->last - cfg->first)) {
+		NL_SET_ERR_MSG_ATTR(info->extack,
+				    tb[ETHTOOL_A_CABLE_TEST_TDR_CFG_STEP],
+				    "step parameter too big");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr *tb[ETHTOOL_A_CABLE_TEST_TDR_MAX + 1];
 	struct ethnl_req_info req_info = {};
+	struct phy_tdr_config cfg;
 	struct net_device *dev;
 	int ret;
 
@@ -235,12 +330,17 @@ int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info)
 		goto out_dev_put;
 	}
 
+	ret = ethnl_act_cable_test_tdr_cfg(tb[ETHTOOL_A_CABLE_TEST_TDR_CFG],
+					   info, &cfg);
+	if (ret)
+		goto out_dev_put;
+
 	rtnl_lock();
 	ret = ethnl_ops_begin(dev);
 	if (ret < 0)
 		goto out_rtnl;
 
-	ret = phy_start_cable_test_tdr(dev->phydev, info->extack);
+	ret = phy_start_cable_test_tdr(dev->phydev, info->extack, &cfg);
 
 	ethnl_ops_complete(dev);