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, 13 insertions, 26 deletions

diff --git a/net/ethtool/tunnels.c b/net/ethtool/tunnels.c
index d93bf2da0f34..330817adcf62 100644
--- a/net/ethtool/tunnels.c
+++ b/net/ethtool/tunnels.c
@@ -8,8 +8,8 @@
 #include "common.h"
 #include "netlink.h"
 
-static const struct nla_policy
-ethtool_tunnel_info_policy[ETHTOOL_A_TUNNEL_INFO_MAX + 1] = {
+const struct nla_policy
+ethnl_tunnel_info_get_policy[ETHTOOL_A_TUNNEL_INFO_MAX + 1] = {
 	[ETHTOOL_A_TUNNEL_INFO_UNSPEC]		= { .type = NLA_REJECT },
 	[ETHTOOL_A_TUNNEL_INFO_HEADER]		= { .type = NLA_NESTED },
 };
@@ -161,35 +161,19 @@ err_cancel_ports:
 	return -EMSGSIZE;
 }
 
-static int
-ethnl_tunnel_info_req_parse(struct ethnl_req_info *req_info,
-			    const struct nlmsghdr *nlhdr, struct net *net,
-			    struct netlink_ext_ack *extack, bool require_dev)
-{
-	struct nlattr *tb[ETHTOOL_A_TUNNEL_INFO_MAX + 1];
-	int ret;
-
-	ret = nlmsg_parse(nlhdr, GENL_HDRLEN, tb, ETHTOOL_A_TUNNEL_INFO_MAX,
-			  ethtool_tunnel_info_policy, extack);
-	if (ret < 0)
-		return ret;
-
-	return ethnl_parse_header_dev_get(req_info,
-					  tb[ETHTOOL_A_TUNNEL_INFO_HEADER],
-					  net, extack, require_dev);
-}
-
 int ethnl_tunnel_info_doit(struct sk_buff *skb, struct genl_info *info)
 {
 	struct ethnl_req_info req_info = {};
+	struct nlattr **tb = info->attrs;
 	struct sk_buff *rskb;
 	void *reply_payload;
 	int reply_len;
 	int ret;
 
-	ret = ethnl_tunnel_info_req_parse(&req_info, info->nlhdr,
-					  genl_info_net(info), info->extack,
-					  true);
+	ret = ethnl_parse_header_dev_get(&req_info,
+					 tb[ETHTOOL_A_TUNNEL_INFO_HEADER],
+					 genl_info_net(info), info->extack,
+					 true);
 	if (ret < 0)
 		return ret;
 
@@ -233,16 +217,19 @@ struct ethnl_tunnel_info_dump_ctx {
 
 int ethnl_tunnel_info_start(struct netlink_callback *cb)
 {
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
 	struct ethnl_tunnel_info_dump_ctx *ctx = (void *)cb->ctx;
+	struct nlattr **tb = info->attrs;
 	int ret;
 
 	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
 
 	memset(ctx, 0, sizeof(*ctx));
 
-	ret = ethnl_tunnel_info_req_parse(&ctx->req_info, cb->nlh,
-					  sock_net(cb->skb->sk), cb->extack,
-					  false);
+	ret = ethnl_parse_header_dev_get(&ctx->req_info,
+					 tb[ETHTOOL_A_TUNNEL_INFO_HEADER],
+					 sock_net(cb->skb->sk), cb->extack,
+					 false);
 	if (ctx->req_info.dev) {
 		dev_put(ctx->req_info.dev);
 		ctx->req_info.dev = NULL;