nexthop: Use a dedicated policy for nh_valid_dump_req()

This function uses the global nexthop policy, but only accepts four
particular attributes. Create a new policy that only includes the four
supported attributes, and use it. Convert the loop to a series of ifs.

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 391079f..bbea78e 100644 (file)
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -40,6 +40,13 @@ static const struct nla_policy rtm_nh_policy_get[] = {
        [NHA_ID]                = { .type = NLA_U32 },
 };
 
+static const struct nla_policy rtm_nh_policy_dump[] = {
+       [NHA_OIF]               = { .type = NLA_U32 },
+       [NHA_GROUPS]            = { .type = NLA_FLAG },
+       [NHA_MASTER]            = { .type = NLA_U32 },
+       [NHA_FDB]               = { .type = NLA_FLAG },
+};
+
 static bool nexthop_notifiers_is_empty(struct net *net)
 {
        return !net->nexthop.notifier_chain.head;
@@ -1983,48 +1990,35 @@ static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx,
                             bool *fdb_filter, struct netlink_callback *cb)
 {
        struct netlink_ext_ack *extack = cb->extack;
-       struct nlattr *tb[NHA_MAX + 1];
+       struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)];
        struct nhmsg *nhm;
-       int err, i;
+       int err;
        u32 idx;
 
-       err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
-                         NULL);
+       err = nlmsg_parse(nlh, sizeof(*nhm), tb,
+                         ARRAY_SIZE(rtm_nh_policy_dump) - 1,
+                         rtm_nh_policy_dump, NULL);
        if (err < 0)
                return err;
 
-       for (i = 0; i <= NHA_MAX; ++i) {
-               if (!tb[i])
-                       continue;
-
-               switch (i) {
-               case NHA_OIF:
-                       idx = nla_get_u32(tb[i]);
-                       if (idx > INT_MAX) {
-                               NL_SET_ERR_MSG(extack, "Invalid device index");
-                               return -EINVAL;
-                       }
-                       *dev_idx = idx;
-                       break;
-               case NHA_MASTER:
-                       idx = nla_get_u32(tb[i]);
-                       if (idx > INT_MAX) {
-                               NL_SET_ERR_MSG(extack, "Invalid master device index");
-                               return -EINVAL;
-                       }
-                       *master_idx = idx;
-                       break;
-               case NHA_GROUPS:
-                       *group_filter = true;
-                       break;
-               case NHA_FDB:
-                       *fdb_filter = true;
-                       break;
-               default:
-                       NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
+       if (tb[NHA_OIF]) {
+               idx = nla_get_u32(tb[NHA_OIF]);
+               if (idx > INT_MAX) {
+                       NL_SET_ERR_MSG(extack, "Invalid device index");
+                       return -EINVAL;
+               }
+               *dev_idx = idx;
+       }
+       if (tb[NHA_MASTER]) {
+               idx = nla_get_u32(tb[NHA_MASTER]);
+               if (idx > INT_MAX) {
+                       NL_SET_ERR_MSG(extack, "Invalid master device index");
                        return -EINVAL;
                }
+               *master_idx = idx;
        }
+       *group_filter = nla_get_flag(tb[NHA_GROUPS]);
+       *fdb_filter = nla_get_flag(tb[NHA_FDB]);
 
        nhm = nlmsg_data(nlh);
        if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {