net_sched: refactor TC action init API

TC action ->init() API has 10 parameters, it becomes harder
to read. Some of them are just boolean and can be replaced
by flags. Similarly for the internal API tcf_action_init()
and tcf_exts_validate().

This patch converts them to flags and fold them into
the upper 16 bits of "flags", whose lower 16 bits are still
reserved for user-space. More specifically, the following
kernel flags are introduced:

TCA_ACT_FLAGS_POLICE replace 'name' in a few contexts, to
distinguish whether it is compatible with policer.

TCA_ACT_FLAGS_BIND replaces 'bind', to indicate whether
this action is bound to a filter.

TCA_ACT_FLAGS_REPLACE  replaces 'ovr' in most contexts,
means we are replacing an existing action.

TCA_ACT_FLAGS_NO_RTNL replaces 'rtnl_held' but has the
opposite meaning, because we still hold RTNL in most
cases.

The only user-space flag TCA_ACT_FLAGS_NO_PERCPU_STATS is
untouched and still stored as before.

I have tested this patch with tdc and I do not see any
failure related to this patch.

Tested-by: Vlad Buslov <vladbu@nvidia.com>
Acked-by: Jamal Hadi Salim<jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 11 deletions

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 7be5b9d2aead..69185e311422 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1949,6 +1949,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	int err;
 	int tp_created;
 	bool rtnl_held = false;
+	u32 flags = 0;
 
 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
@@ -2112,9 +2113,12 @@ replay:
 		goto errout;
 	}
 
+	if (!(n->nlmsg_flags & NLM_F_CREATE))
+		flags |= TCA_ACT_FLAGS_REPLACE;
+	if (!rtnl_held)
+		flags |= TCA_ACT_FLAGS_NO_RTNL;
 	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
-			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
-			      rtnl_held, extack);
+			      flags, extack);
 	if (err == 0) {
 		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
 			       RTM_NEWTFILTER, false, rtnl_held);
@@ -3020,8 +3024,8 @@ void tcf_exts_destroy(struct tcf_exts *exts)
 EXPORT_SYMBOL(tcf_exts_destroy);
 
 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
-		      struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
-		      bool rtnl_held, struct netlink_ext_ack *extack)
+		      struct nlattr *rate_tlv, struct tcf_exts *exts,
+		      u32 flags, struct netlink_ext_ack *extack)
 {
 #ifdef CONFIG_NET_CLS_ACT
 	{
@@ -3032,13 +3036,15 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 		if (exts->police && tb[exts->police]) {
 			struct tc_action_ops *a_o;
 
-			a_o = tc_action_load_ops("police", tb[exts->police], rtnl_held, extack);
+			a_o = tc_action_load_ops(tb[exts->police], true,
+						 !(flags & TCA_ACT_FLAGS_NO_RTNL),
+						 extack);
 			if (IS_ERR(a_o))
 				return PTR_ERR(a_o);
+			flags |= TCA_ACT_FLAGS_POLICE | TCA_ACT_FLAGS_BIND;
 			act = tcf_action_init_1(net, tp, tb[exts->police],
-						rate_tlv, "police", ovr,
-						TCA_ACT_BIND, a_o, init_res,
-						rtnl_held, extack);
+						rate_tlv, a_o, init_res, flags,
+						extack);
 			module_put(a_o->owner);
 			if (IS_ERR(act))
 				return PTR_ERR(act);
@@ -3050,10 +3056,10 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 		} else if (exts->action && tb[exts->action]) {
 			int err;
 
+			flags |= TCA_ACT_FLAGS_BIND;
 			err = tcf_action_init(net, tp, tb[exts->action],
-					      rate_tlv, NULL, ovr, TCA_ACT_BIND,
-					      exts->actions, init_res,
-					      &attr_size, rtnl_held, extack);
+					      rate_tlv, exts->actions, init_res,
+					      &attr_size, flags, extack);
 			if (err < 0)
 				return err;
 			exts->nr_actions = err;