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, 5 insertions, 5 deletions

diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 84c28daff848..c39b583ace32 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -486,13 +486,13 @@ static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
                          unsigned long base, struct tc_u_hnode *ht,
                          struct tc_u_knode *n, struct nlattr **tb,
-                         struct nlattr *est)
+                         struct nlattr *est, bool ovr)
 {
         int err;
         struct tcf_exts e;
 
         tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_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;
 
@@ -545,7 +545,7 @@ errout:
 static int u32_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 tc_u_common *tp_c = tp->data;
         struct tc_u_hnode *ht;
@@ -569,7 +569,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
                         return -EINVAL;
 
                 return u32_set_parms(net, tp, base, n->ht_up, n, tb,
-                                     tca[TCA_RATE]);
+                                     tca[TCA_RATE], ovr);
         }
 
         if (tb[TCA_U32_DIVISOR]) {
@@ -656,7 +656,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
         }
 #endif
 
-        err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE]);
+        err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
         if (err == 0) {
                 struct tc_u_knode **ins;
                 for (ins = &ht->ht[TC_U32_HASH(handle)]; *ins; ins = &(*ins)->next)