ethtool: wire up get policies to ops

Wire up policies for get commands in struct nla_policy of the ethtool
family. Make use of genetlink code attr validation and parsing, as well
as allow dumping policies to user space.

For every ETHTOOL_MSG_*_GET:
 - add 'ethnl_' prefix to policy name
 - add extern declaration in net/ethtool/netlink.h
 - wire up the policy & attr in ethtool_genl_ops[].
 - remove .request_policy and .max_attr from ethnl_request_ops.

Obviously core only records the first "layer" of parsed attrs
so we still need to parse the sub-attrs of the nested header
attribute.

v2:
 - merge of patches 1 and 2 from v1
 - remove stray empty lines in ops
 - also remove .max_attr

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 40 insertions, 22 deletions

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 0c3f54baec4e..be2902285f24 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -247,7 +247,7 @@ static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
 /**
  * ethnl_default_parse() - Parse request message
  * @req_info:    pointer to structure to put data into
- * @nlhdr:       pointer to request message header
+ * @tb:		 parsed attributes
  * @net:         request netns
  * @request_ops: struct request_ops for request type
  * @extack:      netlink extack for error reporting
@@ -259,37 +259,24 @@ static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
  * Return: 0 on success or negative error code
  */
 static int ethnl_default_parse(struct ethnl_req_info *req_info,
-			       const struct nlmsghdr *nlhdr, struct net *net,
+			       struct nlattr **tb, struct net *net,
 			       const struct ethnl_request_ops *request_ops,
 			       struct netlink_ext_ack *extack, bool require_dev)
 {
-	struct nlattr **tb;
 	int ret;
 
-	tb = kmalloc_array(request_ops->max_attr + 1, sizeof(tb[0]),
-			   GFP_KERNEL);
-	if (!tb)
-		return -ENOMEM;
-
-	ret = nlmsg_parse(nlhdr, GENL_HDRLEN, tb, request_ops->max_attr,
-			  request_ops->request_policy, extack);
-	if (ret < 0)
-		goto out;
 	ret = ethnl_parse_header_dev_get(req_info, tb[request_ops->hdr_attr],
 					 net, extack, require_dev);
 	if (ret < 0)
-		goto out;
+		return ret;
 
 	if (request_ops->parse_request) {
 		ret = request_ops->parse_request(req_info, tb, extack);
 		if (ret < 0)
-			goto out;
+			return ret;
 	}
 
-	ret = 0;
-out:
-	kfree(tb);
-	return ret;
+	return 0;
 }
 
 /**
@@ -334,8 +321,8 @@ static int ethnl_default_doit(struct sk_buff *skb, struct genl_info *info)
 		return -ENOMEM;
 	}
 
-	ret = ethnl_default_parse(req_info, info->nlhdr, genl_info_net(info), ops,
-				  info->extack, !ops->allow_nodev_do);
+	ret = ethnl_default_parse(req_info, info->attrs, genl_info_net(info),
+				  ops, info->extack, !ops->allow_nodev_do);
 	if (ret < 0)
 		goto err_dev;
 	ethnl_init_reply_data(reply_data, ops, req_info->dev);
@@ -480,6 +467,7 @@ out:
 /* generic ->start() handler for GET requests */
 static int ethnl_default_start(struct netlink_callback *cb)
 {
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
 	struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
 	struct ethnl_reply_data *reply_data;
 	const struct ethnl_request_ops *ops;
@@ -502,8 +490,8 @@ static int ethnl_default_start(struct netlink_callback *cb)
 		goto free_req_info;
 	}
 
-	ret = ethnl_default_parse(req_info, cb->nlh, sock_net(cb->skb->sk), ops,
-				  cb->extack, false);
+	ret = ethnl_default_parse(req_info, info->attrs, sock_net(cb->skb->sk),
+				  ops, cb->extack, false);
 	if (req_info->dev) {
 		/* We ignore device specification in dump requests but as the
 		 * same parser as for non-dump (doit) requests is used, it
@@ -696,6 +684,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_strset_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_strset_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_LINKINFO_GET,
@@ -703,6 +693,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_linkinfo_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_linkinfo_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_LINKINFO_SET,
@@ -715,6 +707,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_linkmodes_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_linkmodes_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_LINKMODES_SET,
@@ -727,6 +721,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_linkstate_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_linkstate_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_DEBUG_GET,
@@ -734,6 +730,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_debug_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_debug_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_DEBUG_SET,
@@ -747,6 +745,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_wol_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_wol_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_WOL_SET,
@@ -759,6 +759,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_features_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_features_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_FEATURES_SET,
@@ -771,6 +773,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_privflags_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_privflags_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_PRIVFLAGS_SET,
@@ -783,6 +787,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_rings_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_rings_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_RINGS_SET,
@@ -795,6 +801,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_channels_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_channels_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_CHANNELS_SET,
@@ -807,6 +815,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_coalesce_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_coalesce_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_COALESCE_SET,
@@ -819,6 +829,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_pause_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_pause_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_PAUSE_SET,
@@ -831,6 +843,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_eee_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_eee_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_EEE_SET,
@@ -843,6 +857,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.start	= ethnl_default_start,
 		.dumpit	= ethnl_default_dumpit,
 		.done	= ethnl_default_done,
+		.policy = ethnl_tsinfo_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_tsinfo_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_CABLE_TEST_ACT,
@@ -859,6 +875,8 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.doit	= ethnl_tunnel_info_doit,
 		.start	= ethnl_tunnel_info_start,
 		.dumpit	= ethnl_tunnel_info_dumpit,
+		.policy = ethnl_tunnel_info_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_tunnel_info_get_policy) - 1,
 	},
 };