Merge branch 'ethtool-allow-dumping-policies-to-user-space'

Jakub Kicinski says:

====================
ethtool: allow dumping policies to user space

This series wires up ethtool policies to ops, so they can be
dumped to user space for feature discovery.

First patch wires up GET commands, and second patch wires up SETs.

The policy tables are trimmed to save space and LoC.

Next - take care of linking up nested policies for the header
(which is the policy what we actually care about). And once header
policy is linked make sure that attribute range validation for flags
is done by policy, not a conditions in the code. New type of policy
is needed to validate masks (patch 6).

Netlink as always staying a step ahead of all the other kernel
API interfaces :)

v2:
 - merge patches 1 & 2 -> 1
 - add patch 3 & 5
 - remove .max_attr from struct ethnl_request_ops
====================

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 23 deletions

diff --git a/net/ethtool/features.c b/net/ethtool/features.c
index 495635f152ba..8ee4cdbd6b82 100644
--- a/net/ethtool/features.c
+++ b/net/ethtool/features.c
@@ -20,14 +20,9 @@ struct features_reply_data {
 #define FEATURES_REPDATA(__reply_base) \
 	container_of(__reply_base, struct features_reply_data, base)
 
-static const struct nla_policy
-features_get_policy[ETHTOOL_A_FEATURES_MAX + 1] = {
-	[ETHTOOL_A_FEATURES_UNSPEC]	= { .type = NLA_REJECT },
-	[ETHTOOL_A_FEATURES_HEADER]	= { .type = NLA_NESTED },
-	[ETHTOOL_A_FEATURES_HW]		= { .type = NLA_REJECT },
-	[ETHTOOL_A_FEATURES_WANTED]	= { .type = NLA_REJECT },
-	[ETHTOOL_A_FEATURES_ACTIVE]	= { .type = NLA_REJECT },
-	[ETHTOOL_A_FEATURES_NOCHANGE]	= { .type = NLA_REJECT },
+const struct nla_policy ethnl_features_get_policy[] = {
+	[ETHTOOL_A_FEATURES_HEADER]	=
+		NLA_POLICY_NESTED(ethnl_header_policy),
 };
 
 static void ethnl_features_to_bitmap32(u32 *dest, netdev_features_t src)
@@ -120,10 +115,8 @@ const struct ethnl_request_ops ethnl_features_request_ops = {
 	.request_cmd		= ETHTOOL_MSG_FEATURES_GET,
 	.reply_cmd		= ETHTOOL_MSG_FEATURES_GET_REPLY,
 	.hdr_attr		= ETHTOOL_A_FEATURES_HEADER,
-	.max_attr		= ETHTOOL_A_FEATURES_MAX,
 	.req_info_size		= sizeof(struct features_req_info),
 	.reply_data_size	= sizeof(struct features_reply_data),
-	.request_policy		= features_get_policy,
 
 	.prepare_data		= features_prepare_data,
 	.reply_size		= features_reply_size,
@@ -132,14 +125,10 @@ const struct ethnl_request_ops ethnl_features_request_ops = {
 
 /* FEATURES_SET */
 
-static const struct nla_policy
-features_set_policy[ETHTOOL_A_FEATURES_MAX + 1] = {
-	[ETHTOOL_A_FEATURES_UNSPEC]	= { .type = NLA_REJECT },
-	[ETHTOOL_A_FEATURES_HEADER]	= { .type = NLA_NESTED },
-	[ETHTOOL_A_FEATURES_HW]		= { .type = NLA_REJECT },
+const struct nla_policy ethnl_features_set_policy[] = {
+	[ETHTOOL_A_FEATURES_HEADER]	=
+		NLA_POLICY_NESTED(ethnl_header_policy),
 	[ETHTOOL_A_FEATURES_WANTED]	= { .type = NLA_NESTED },
-	[ETHTOOL_A_FEATURES_ACTIVE]	= { .type = NLA_REJECT },
-	[ETHTOOL_A_FEATURES_NOCHANGE]	= { .type = NLA_REJECT },
 };
 
 static void ethnl_features_to_bitmap(unsigned long *dest, netdev_features_t val)
@@ -229,17 +218,12 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
 	DECLARE_BITMAP(new_wanted, NETDEV_FEATURE_COUNT);
 	DECLARE_BITMAP(req_wanted, NETDEV_FEATURE_COUNT);
 	DECLARE_BITMAP(req_mask, NETDEV_FEATURE_COUNT);
-	struct nlattr *tb[ETHTOOL_A_FEATURES_MAX + 1];
 	struct ethnl_req_info req_info = {};
+	struct nlattr **tb = info->attrs;
 	struct net_device *dev;
 	bool mod;
 	int ret;
 
-	ret = nlmsg_parse(info->nlhdr, GENL_HDRLEN, tb,
-			  ETHTOOL_A_FEATURES_MAX, features_set_policy,
-			  info->extack);
-	if (ret < 0)
-		return ret;
 	if (!tb[ETHTOOL_A_FEATURES_WANTED])
 		return -EINVAL;
 	ret = ethnl_parse_header_dev_get(&req_info,