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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

1 files changed, 88 insertions, 36 deletions

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 0c3f54baec4e..8a85a4e6be9b 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -9,12 +9,24 @@ static struct genl_family ethtool_genl_family;
 static bool ethnl_ok __read_mostly;
 static u32 ethnl_bcast_seq;
 
-static const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_MAX + 1] = {
-	[ETHTOOL_A_HEADER_UNSPEC]	= { .type = NLA_REJECT },
+#define ETHTOOL_FLAGS_BASIC (ETHTOOL_FLAG_COMPACT_BITSETS |	\
+			     ETHTOOL_FLAG_OMIT_REPLY)
+#define ETHTOOL_FLAGS_STATS (ETHTOOL_FLAGS_BASIC | ETHTOOL_FLAG_STATS)
+
+const struct nla_policy ethnl_header_policy[] = {
 	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
 	[ETHTOOL_A_HEADER_DEV_NAME]	= { .type = NLA_NUL_STRING,
 					    .len = ALTIFNAMSIZ - 1 },
-	[ETHTOOL_A_HEADER_FLAGS]	= { .type = NLA_U32 },
+	[ETHTOOL_A_HEADER_FLAGS]	= NLA_POLICY_MASK(NLA_U32,
+							  ETHTOOL_FLAGS_BASIC),
+};
+
+const struct nla_policy ethnl_header_policy_stats[] = {
+	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
+	[ETHTOOL_A_HEADER_DEV_NAME]	= { .type = NLA_NUL_STRING,
+					    .len = ALTIFNAMSIZ - 1 },
+	[ETHTOOL_A_HEADER_FLAGS]	= NLA_POLICY_MASK(NLA_U32,
+							  ETHTOOL_FLAGS_STATS),
 };
 
 /**
@@ -37,7 +49,7 @@ int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
 			       const struct nlattr *header, struct net *net,
 			       struct netlink_ext_ack *extack, bool require_dev)
 {
-	struct nlattr *tb[ETHTOOL_A_HEADER_MAX + 1];
+	struct nlattr *tb[ARRAY_SIZE(ethnl_header_policy)];
 	const struct nlattr *devname_attr;
 	struct net_device *dev = NULL;
 	u32 flags = 0;
@@ -47,19 +59,15 @@ int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
 		NL_SET_ERR_MSG(extack, "request header missing");
 		return -EINVAL;
 	}
-	ret = nla_parse_nested(tb, ETHTOOL_A_HEADER_MAX, header,
-			       ethnl_header_policy, extack);
+	/* No validation here, command policy should have a nested policy set
+	 * for the header, therefore validation should have already been done.
+	 */
+	ret = nla_parse_nested(tb, ARRAY_SIZE(ethnl_header_policy) - 1, header,
+			       NULL, extack);
 	if (ret < 0)
 		return ret;
-	if (tb[ETHTOOL_A_HEADER_FLAGS]) {
+	if (tb[ETHTOOL_A_HEADER_FLAGS])
 		flags = nla_get_u32(tb[ETHTOOL_A_HEADER_FLAGS]);
-		if (flags & ~ETHTOOL_FLAG_ALL) {
-			NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_HEADER_FLAGS],
-					    "unrecognized request flags");
-			nl_set_extack_cookie_u32(extack, ETHTOOL_FLAG_ALL);
-			return -EOPNOTSUPP;
-		}
-	}
 
 	devname_attr = tb[ETHTOOL_A_HEADER_DEV_NAME];
 	if (tb[ETHTOOL_A_HEADER_DEV_INDEX]) {
@@ -247,7 +255,7 @@ 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 +267,24 @@ 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 +329,8 @@ 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 +475,7 @@ 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 +498,8 @@ 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 +692,8 @@ 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,
@@ -703,11 +701,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_linkinfo,
+		.policy = ethnl_linkinfo_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_linkinfo_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_LINKMODES_GET,
@@ -715,11 +717,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_linkmodes,
+		.policy = ethnl_linkmodes_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_linkmodes_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_LINKSTATE_GET,
@@ -727,6 +733,8 @@ 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,
@@ -734,11 +742,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_debug,
+		.policy = ethnl_debug_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_debug_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_WOL_GET,
@@ -747,11 +759,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_wol,
+		.policy = ethnl_wol_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_wol_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_FEATURES_GET,
@@ -759,11 +775,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_features,
+		.policy = ethnl_features_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_features_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_PRIVFLAGS_GET,
@@ -771,11 +791,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_privflags,
+		.policy = ethnl_privflags_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_privflags_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_RINGS_GET,
@@ -783,11 +807,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_rings,
+		.policy = ethnl_rings_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_rings_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_CHANNELS_GET,
@@ -795,11 +823,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_channels,
+		.policy = ethnl_channels_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_channels_get_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_COALESCE_GET,
@@ -807,11 +839,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_coalesce,
+		.policy = ethnl_coalesce_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_coalesce_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_PAUSE_GET,
@@ -819,11 +855,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_pause,
+		.policy = ethnl_pause_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_pause_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_EEE_GET,
@@ -831,11 +871,15 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_eee,
+		.policy = ethnl_eee_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_eee_set_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_TSINFO_GET,
@@ -843,22 +887,30 @@ 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,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_act_cable_test,
+		.policy = ethnl_cable_test_act_policy,
+		.maxattr = ARRAY_SIZE(ethnl_cable_test_act_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_CABLE_TEST_TDR_ACT,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_act_cable_test_tdr,
+		.policy = ethnl_cable_test_tdr_act_policy,
+		.maxattr = ARRAY_SIZE(ethnl_cable_test_tdr_act_policy) - 1,
 	},
 	{
 		.cmd	= ETHTOOL_MSG_TUNNEL_INFO_GET,
 		.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,
 	},
 };