sched, cls: check if we could overwrite actions when changing a filter

When actions are attached to a filter, they are a part of the filter
itself, so when changing a filter we should allow to overwrite the actions
inside as well.

In my specific case, when I tried to _append_ a new action to an existing
filter which already has an action, I got EEXIST since kernel refused
to overwrite the existing one in kernel.

This patch checks if we are changing the filter checking NLM_F_CREATE flag
(Sigh, filters don't use NLM_F_REPLACE...) and then passes the boolean down
to actions. This fixes the problem above.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h
index 19f8e5d..1020e23 100644
--- a/net/sched/cls_rsvp.h
+++ b/net/sched/cls_rsvp.h
@@ -415,7 +415,7 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle,
 		       struct nlattr **tca,
-		       unsigned long *arg)
+		       unsigned long *arg, bool ovr)
 {
 	struct rsvp_head *data = tp->root;
 	struct rsvp_filter *f, **fp;
@@ -436,7 +436,7 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb,
 		return err;
 
 	tcf_exts_init(&e, TCA_RSVP_ACT, TCA_RSVP_POLICE);
-	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e);
+	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
 	if (err < 0)
 		return err;