nexthop: Use a dedicated policy for nh_valid_get_del_req()

This function uses the global nexthop policy only to then bounce all
arguments except for NHA_ID. Instead, just create a new policy that
only includes the one allowed attribute.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index e53e43a..391079f 100644 (file)
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -36,6 +36,10 @@ static const struct nla_policy rtm_nh_policy[NHA_MAX + 1] = {
        [NHA_FDB]               = { .type = NLA_FLAG },
 };
 
+static const struct nla_policy rtm_nh_policy_get[] = {
+       [NHA_ID]                = { .type = NLA_U32 },
+};
+
 static bool nexthop_notifiers_is_empty(struct net *net)
 {
        return !net->nexthop.notifier_chain.head;
@@ -1842,28 +1846,16 @@ static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id,
                                struct netlink_ext_ack *extack)
 {
        struct nhmsg *nhm = nlmsg_data(nlh);
-       struct nlattr *tb[NHA_MAX + 1];
-       int err, i;
+       struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)];
+       int err;
 
-       err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
-                         extack);
+       err = nlmsg_parse(nlh, sizeof(*nhm), tb,
+                         ARRAY_SIZE(rtm_nh_policy_get) - 1,
+                         rtm_nh_policy_get, extack);
        if (err < 0)
                return err;
 
        err = -EINVAL;
-       for (i = 0; i < __NHA_MAX; ++i) {
-               if (!tb[i])
-                       continue;
-
-               switch (i) {
-               case NHA_ID:
-                       break;
-               default:
-                       NL_SET_ERR_MSG_ATTR(extack, tb[i],
-                                           "Unexpected attribute in request");
-                       goto out;
-               }
-       }
        if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
                NL_SET_ERR_MSG(extack, "Invalid values in header");
                goto out;