[PATCH net-next 1/3] nexthop: Use a dedicated policy for nh_valid_get_del_req()

[Petr Machata]

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 <pe...@nvidia.com>
Reviewed-by: Ido Schimmel <ido...@nvidia.com>
---
 net/ipv4/nexthop.c | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index e53e43aef785..d5d88f7c5c11 100644
--- 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_MAX + 1] = {
+       [NHA_ID]                = { .type = NLA_U32 },
+};
+
 static bool nexthop_notifiers_is_empty(struct net *net)
 {
        return !net->nexthop.notifier_chain.head;
@@ -1843,27 +1847,14 @@ static int nh_valid_get_del_req(struct nlmsghdr *nlh, 
u32 *id,
 {
        struct nhmsg *nhm = nlmsg_data(nlh);
        struct nlattr *tb[NHA_MAX + 1];
-       int err, i;
+       int err;
 
-       err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
+       err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, 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;
-- 
2.26.2