net sched: skbedit action fix late binding

The process below was broken and is fixed with this patch.

//add a skbedit action and give it an instance id of 1
sudo tc actions add action skbedit mark 10 index 1
//create a filter which binds to skbedit action id 1
sudo tc filter add dev $DEV parent ffff: protocol ip prio 1 u32\
match ip dst 17.0.0.1/32 flowid 1:10 action skbedit index 1

Message before fix was:
RTNETLINK answers: Invalid argument
We have an error talking to the kernel

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index cfcdbdc00c9bfef4702ae09875080cc0b3df11ea..69da5a8f0034eb8851a124863cf876324862138d 100644 (file)
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c
@@ -69,7 +69,7 @@ static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
        struct tcf_skbedit *d;
        u32 flags = 0, *priority = NULL, *mark = NULL;
        u16 *queue_mapping = NULL;
-       int ret = 0, err;
+       int ret = 0, err, exists = 0;
 
        if (nla == NULL)
                return -EINVAL;
@@ -96,12 +96,18 @@ static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
                mark = nla_data(tb[TCA_SKBEDIT_MARK]);
        }
 
-       if (!flags)
-               return -EINVAL;
-
        parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
 
-       if (!tcf_hash_check(tn, parm->index, a, bind)) {
+       exists = tcf_hash_check(tn, parm->index, a, bind);
+       if (exists && bind)
+               return 0;
+
+       if (!flags) {
+               tcf_hash_release(a, bind);
+               return -EINVAL;
+       }
+
+       if (!exists) {
                ret = tcf_hash_create(tn, parm->index, est, a,
                                      sizeof(*d), bind, false);
                if (ret)
@@ -111,8 +117,6 @@ static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
                ret = ACT_P_CREATED;
        } else {
                d = to_skbedit(a);
-               if (bind)
-                       return 0;
                tcf_hash_release(a, bind);
                if (!ovr)
                        return -EEXIST;