nexthop: Only parse NHA_OP_FLAGS for get messages that require it

The attribute is parsed into 'op_flags' in nh_valid_get_del_req() which
is called from the handlers of three message types: RTM_DELNEXTHOP,
RTM_GETNEXTHOPBUCKET and RTM_GETNEXTHOP. The attribute is only used by
the latter and rejected by the policies of the other two.

Pass 'op_flags' as NULL from the handlers of the other two and only
parse the attribute when the argument is not NULL.

This is a preparation for a subsequent patch.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240311162307.545385-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 73b849be65042acfd0650e49aa7233c7f6a51f2e..6901fa39065117228cfbd7aebbce6bf3a3094586 100644 (file)
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -3230,10 +3230,12 @@ static int nh_valid_get_del_req(const struct nlmsghdr *nlh,
                return -EINVAL;
        }
 
-       if (tb[NHA_OP_FLAGS])
-               *op_flags = nla_get_u32(tb[NHA_OP_FLAGS]);
-       else
-               *op_flags = 0;
+       if (op_flags) {
+               if (tb[NHA_OP_FLAGS])
+                       *op_flags = nla_get_u32(tb[NHA_OP_FLAGS]);
+               else
+                       *op_flags = 0;
+       }
 
        return 0;
 }
@@ -3250,7 +3252,6 @@ static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
                .portid = NETLINK_CB(skb).portid,
        };
        struct nexthop *nh;
-       u32 op_flags;
        int err;
        u32 id;
 
@@ -3259,7 +3260,7 @@ static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
        if (err < 0)
                return err;
 
-       err = nh_valid_get_del_req(nlh, tb, &id, &op_flags, extack);
+       err = nh_valid_get_del_req(nlh, tb, &id, NULL, extack);
        if (err)
                return err;
 
@@ -3716,7 +3717,6 @@ static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh,
                                   struct netlink_ext_ack *extack)
 {
        struct nlattr *tb[NHA_MAX + 1];
-       u32 op_flags;
        int err;
 
        err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, NHA_MAX,
@@ -3724,7 +3724,7 @@ static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh,
        if (err < 0)
                return err;
 
-       err = nh_valid_get_del_req(nlh, tb, id, &op_flags, extack);
+       err = nh_valid_get_del_req(nlh, tb, id, NULL, extack);
        if (err)
                return err;