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, 31 insertions, 30 deletions

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 998a2374f7ae..7dd3a2dc5fa4 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -495,7 +495,7 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 	p->tcfa_tm.install = jiffies;
 	p->tcfa_tm.lastuse = jiffies;
 	p->tcfa_tm.firstuse = 0;
-	p->tcfa_flags = flags;
+	p->tcfa_flags = flags & TCA_ACT_FLAGS_USER_MASK;
 	if (est) {
 		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 					&p->tcfa_rate_est,
@@ -941,7 +941,7 @@ void tcf_idr_insert_many(struct tc_action *actions[])
 	}
 }
 
-struct tc_action_ops *tc_action_load_ops(char *name, struct nlattr *nla,
+struct tc_action_ops *tc_action_load_ops(struct nlattr *nla, bool police,
 					 bool rtnl_held,
 					 struct netlink_ext_ack *extack)
 {
@@ -951,7 +951,7 @@ struct tc_action_ops *tc_action_load_ops(char *name, struct nlattr *nla,
 	struct nlattr *kind;
 	int err;
 
-	if (name == NULL) {
+	if (!police) {
 		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 						  tcf_action_policy, extack);
 		if (err < 0)
@@ -967,7 +967,7 @@ struct tc_action_ops *tc_action_load_ops(char *name, struct nlattr *nla,
 			return ERR_PTR(err);
 		}
 	} else {
-		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
+		if (strlcpy(act_name, "police", IFNAMSIZ) >= IFNAMSIZ) {
 			NL_SET_ERR_MSG(extack, "TC action name too long");
 			return ERR_PTR(-EINVAL);
 		}
@@ -1004,12 +1004,11 @@ struct tc_action_ops *tc_action_load_ops(char *name, struct nlattr *nla,
 
 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 				    struct nlattr *nla, struct nlattr *est,
-				    char *name, int ovr, int bind,
 				    struct tc_action_ops *a_o, int *init_res,
-				    bool rtnl_held,
-				    struct netlink_ext_ack *extack)
+				    u32 flags, struct netlink_ext_ack *extack)
 {
-	struct nla_bitfield32 flags = { 0, 0 };
+	bool police = flags & TCA_ACT_FLAGS_POLICE;
+	struct nla_bitfield32 userflags = { 0, 0 };
 	u8 hw_stats = TCA_ACT_HW_STATS_ANY;
 	struct nlattr *tb[TCA_ACT_MAX + 1];
 	struct tc_cookie *cookie = NULL;
@@ -1017,7 +1016,7 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 	int err;
 
 	/* backward compatibility for policer */
-	if (name == NULL) {
+	if (!police) {
 		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 						  tcf_action_policy, extack);
 		if (err < 0)
@@ -1032,22 +1031,22 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 		}
 		hw_stats = tcf_action_hw_stats_get(tb[TCA_ACT_HW_STATS]);
 		if (tb[TCA_ACT_FLAGS])
-			flags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
+			userflags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
 
-		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
-				rtnl_held, tp, flags.value, extack);
+		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, tp,
+				userflags.value | flags, extack);
 	} else {
-		err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
-				tp, flags.value, extack);
+		err = a_o->init(net, nla, est, &a, tp, userflags.value | flags,
+				extack);
 	}
 	if (err < 0)
 		goto err_out;
 	*init_res = err;
 
-	if (!name && tb[TCA_ACT_COOKIE])
+	if (!police && tb[TCA_ACT_COOKIE])
 		tcf_set_action_cookie(&a->act_cookie, cookie);
 
-	if (!name)
+	if (!police)
 		a->hw_stats = hw_stats;
 
 	return a;
@@ -1063,9 +1062,9 @@ err_out:
 /* Returns numbers of initialized actions or negative error. */
 
 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
-		    struct nlattr *est, char *name, int ovr, int bind,
-		    struct tc_action *actions[], int init_res[], size_t *attr_size,
-		    bool rtnl_held, struct netlink_ext_ack *extack)
+		    struct nlattr *est, struct tc_action *actions[],
+		    int init_res[], size_t *attr_size, u32 flags,
+		    struct netlink_ext_ack *extack)
 {
 	struct tc_action_ops *ops[TCA_ACT_MAX_PRIO] = {};
 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
@@ -1082,7 +1081,9 @@ int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 		struct tc_action_ops *a_o;
 
-		a_o = tc_action_load_ops(name, tb[i], rtnl_held, extack);
+		a_o = tc_action_load_ops(tb[i], flags & TCA_ACT_FLAGS_POLICE,
+					 !(flags & TCA_ACT_FLAGS_NO_RTNL),
+					 extack);
 		if (IS_ERR(a_o)) {
 			err = PTR_ERR(a_o);
 			goto err_mod;
@@ -1091,9 +1092,8 @@ int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 	}
 
 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
-		act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
-					ops[i - 1], &init_res[i - 1], rtnl_held,
-					extack);
+		act = tcf_action_init_1(net, tp, tb[i], est, ops[i - 1],
+					&init_res[i - 1], flags, extack);
 		if (IS_ERR(act)) {
 			err = PTR_ERR(act);
 			goto err;
@@ -1113,7 +1113,7 @@ int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 	goto err_mod;
 
 err:
-	tcf_action_destroy(actions, bind);
+	tcf_action_destroy(actions, flags & TCA_ACT_FLAGS_BIND);
 err_mod:
 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 		if (ops[i])
@@ -1495,7 +1495,7 @@ tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
 }
 
 static int tcf_action_add(struct net *net, struct nlattr *nla,
-			  struct nlmsghdr *n, u32 portid, int ovr,
+			  struct nlmsghdr *n, u32 portid, u32 flags,
 			  struct netlink_ext_ack *extack)
 {
 	size_t attr_size = 0;
@@ -1504,8 +1504,8 @@ static int tcf_action_add(struct net *net, struct nlattr *nla,
 	int init_res[TCA_ACT_MAX_PRIO] = {};
 
 	for (loop = 0; loop < 10; loop++) {
-		ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
-				      actions, init_res, &attr_size, true, extack);
+		ret = tcf_action_init(net, NULL, nla, NULL, actions, init_res,
+				      &attr_size, flags, extack);
 		if (ret != -EAGAIN)
 			break;
 	}
@@ -1535,7 +1535,8 @@ static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
 	struct net *net = sock_net(skb->sk);
 	struct nlattr *tca[TCA_ROOT_MAX + 1];
 	u32 portid = NETLINK_CB(skb).portid;
-	int ret = 0, ovr = 0;
+	u32 flags = 0;
+	int ret = 0;
 
 	if ((n->nlmsg_type != RTM_GETACTION) &&
 	    !netlink_capable(skb, CAP_NET_ADMIN))
@@ -1561,8 +1562,8 @@ static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
 		 * is zero) then just set this
 		 */
 		if (n->nlmsg_flags & NLM_F_REPLACE)
-			ovr = 1;
-		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
+			flags = TCA_ACT_FLAGS_REPLACE;
+		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, flags,
 				     extack);
 		break;
 	case RTM_DELACTION: