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, 4 insertions, 4 deletions

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index eed8404443d8..d11d0a4fbe34 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -192,7 +192,7 @@ static int
 tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
                   u32 handle, struct tcindex_data *p,
                   struct tcindex_filter_result *r, struct nlattr **tb,
-                 struct nlattr *est)
+                  struct nlattr *est, bool ovr)
 {
         int err, balloc = 0;
         struct tcindex_filter_result new_filter_result, *old_r = r;
@@ -202,7 +202,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
         struct tcf_exts e;
 
         tcf_exts_init(&e, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
-        err = tcf_exts_validate(net, tp, tb, est, &e);
+        err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
         if (err < 0)
                 return err;
 
@@ -331,7 +331,7 @@ errout:
 static int
 tcindex_change(struct net *net, struct sk_buff *in_skb,
                struct tcf_proto *tp, unsigned long base, u32 handle,
-               struct nlattr **tca, unsigned long *arg)
+               struct nlattr **tca, unsigned long *arg, bool ovr)
 {
         struct nlattr *opt = tca[TCA_OPTIONS];
         struct nlattr *tb[TCA_TCINDEX_MAX + 1];
@@ -351,7 +351,7 @@ tcindex_change(struct net *net, struct sk_buff *in_skb,
                 return err;
 
         return tcindex_set_parms(net, tp, base, handle, p, r, tb,
-                                 tca[TCA_RATE]);
+                                 tca[TCA_RATE], ovr);
 }