net_sched: move tc_action into tcf_common

struct tc_action is confusing, currently we use it for two purposes:
1) Pass in arguments and carry out results from helper functions
2) A generic representation for tc actions

The first one is error-prone, since we need to make sure we don't
miss anything. This patch aims to get rid of this use, by moving
tc_action into tcf_common, so that they are allocated together
in hashtable and can be cast'ed easily.

And together with the following patch, we could really make
tc_action a generic representation for all tc actions and each
type of action can inherit from it.

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

1 files changed, 12 insertions, 10 deletions

diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
index dcd9ababd351..b5dbf633a863 100644
--- a/net/sched/act_csum.c
+++ b/net/sched/act_csum.c
@@ -43,9 +43,10 @@ static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
 };
 
 static int csum_net_id;
+static struct tc_action_ops act_csum_ops;
 
 static int tcf_csum_init(struct net *net, struct nlattr *nla,
-			 struct nlattr *est, struct tc_action *a, int ovr,
+			 struct nlattr *est, struct tc_action **a, int ovr,
 			 int bind)
 {
 	struct tc_action_net *tn = net_generic(net, csum_net_id);
@@ -67,26 +68,26 @@ static int tcf_csum_init(struct net *net, struct nlattr *nla,
 
 	if (!tcf_hash_check(tn, parm->index, a, bind)) {
 		ret = tcf_hash_create(tn, parm->index, est, a,
-				      sizeof(*p), bind, false);
+				      &act_csum_ops, bind, false);
 		if (ret)
 			return ret;
 		ret = ACT_P_CREATED;
 	} else {
 		if (bind)/* dont override defaults */
 			return 0;
-		tcf_hash_release(a, bind);
+		tcf_hash_release(*a, bind);
 		if (!ovr)
 			return -EEXIST;
 	}
 
-	p = to_tcf_csum(a);
+	p = to_tcf_csum(*a);
 	spin_lock_bh(&p->tcf_lock);
 	p->tcf_action = parm->action;
 	p->update_flags = parm->update_flags;
 	spin_unlock_bh(&p->tcf_lock);
 
 	if (ret == ACT_P_CREATED)
-		tcf_hash_insert(tn, a);
+		tcf_hash_insert(tn, *a);
 
 	return ret;
 }
@@ -496,7 +497,7 @@ fail:
 static int tcf_csum(struct sk_buff *skb,
 		    const struct tc_action *a, struct tcf_result *res)
 {
-	struct tcf_csum *p = a->priv;
+	struct tcf_csum *p = to_tcf_csum(a);
 	int action;
 	u32 update_flags;
 
@@ -534,7 +535,7 @@ static int tcf_csum_dump(struct sk_buff *skb,
 			 struct tc_action *a, int bind, int ref)
 {
 	unsigned char *b = skb_tail_pointer(skb);
-	struct tcf_csum *p = a->priv;
+	struct tcf_csum *p = to_tcf_csum(a);
 	struct tc_csum opt = {
 		.update_flags = p->update_flags,
 		.index   = p->tcf_index,
@@ -560,14 +561,14 @@ nla_put_failure:
 
 static int tcf_csum_walker(struct net *net, struct sk_buff *skb,
 			   struct netlink_callback *cb, int type,
-			   struct tc_action *a)
+			   const struct tc_action_ops *ops)
 {
 	struct tc_action_net *tn = net_generic(net, csum_net_id);
 
-	return tcf_generic_walker(tn, skb, cb, type, a);
+	return tcf_generic_walker(tn, skb, cb, type, ops);
 }
 
-static int tcf_csum_search(struct net *net, struct tc_action *a, u32 index)
+static int tcf_csum_search(struct net *net, struct tc_action **a, u32 index)
 {
 	struct tc_action_net *tn = net_generic(net, csum_net_id);
 
@@ -583,6 +584,7 @@ static struct tc_action_ops act_csum_ops = {
 	.init		= tcf_csum_init,
 	.walk		= tcf_csum_walker,
 	.lookup		= tcf_csum_search,
+	.size		= sizeof(struct tcf_csum),
 };
 
 static __net_init int csum_init_net(struct net *net)