On Mon, 18 Jan 2021 15:05:23 +0100 Petr Machata wrote:
> 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] = {
This is an unnecessary waste of memory if you ask me.
NHA_ID is 1, so we're creating an array of 10 extra NULL elements.
Can you leave the size to the compiler and use ARRAY_SIZE() below?
> + [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;
