net: sched: implement terse dump support in act

Extend tcf_action_dump() with boolean argument 'terse' that is used to
request terse-mode action dump. In terse mode only essential data needed to
identify particular action (action kind, cookie, etc.) and its stats is put
to resulting skb and everything else is omitted. Implement
tcf_exts_terse_dump() helper in cls API that is intended to be used to
request terse dump of all exts (actions) attached to the filter.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 50 insertions, 8 deletions

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index fbbec2e562f5..8ac7eb0a8309 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -766,12 +766,10 @@ tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 	return a->ops->dump(skb, a, bind, ref);
 }
 
-int
-tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
+static int
+tcf_action_dump_terse(struct sk_buff *skb, struct tc_action *a)
 {
-	int err = -EINVAL;
 	unsigned char *b = skb_tail_pointer(skb);
-	struct nlattr *nest;
 	struct tc_cookie *cookie;
 
 	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
@@ -789,6 +787,23 @@ tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 	}
 	rcu_read_unlock();
 
+	return 0;
+
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+int
+tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
+{
+	int err = -EINVAL;
+	unsigned char *b = skb_tail_pointer(skb);
+	struct nlattr *nest;
+
+	if (tcf_action_dump_terse(skb, a))
+		goto nla_put_failure;
+
 	if (a->hw_stats != TCA_ACT_HW_STATS_ANY &&
 	    nla_put_bitfield32(skb, TCA_ACT_HW_STATS,
 			       a->hw_stats, TCA_ACT_HW_STATS_ANY))
@@ -820,7 +835,7 @@ nla_put_failure:
 EXPORT_SYMBOL(tcf_action_dump_1);
 
 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
-		    int bind, int ref)
+		    int bind, int ref, bool terse)
 {
 	struct tc_action *a;
 	int err = -EINVAL, i;
@@ -831,7 +846,8 @@ int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 		nest = nla_nest_start_noflag(skb, i + 1);
 		if (nest == NULL)
 			goto nla_put_failure;
-		err = tcf_action_dump_1(skb, a, bind, ref);
+		err = terse ? tcf_action_dump_terse(skb, a) :
+			tcf_action_dump_1(skb, a, bind, ref);
 		if (err < 0)
 			goto errout;
 		nla_nest_end(skb, nest);
@@ -1133,7 +1149,7 @@ static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
 	if (!nest)
 		goto out_nlmsg_trim;
 
-	if (tcf_action_dump(skb, actions, bind, ref) < 0)
+	if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
 		goto out_nlmsg_trim;
 
 	nla_nest_end(skb, nest);
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index cb2c10e0fee5..752d608f4442 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -3179,7 +3179,8 @@ int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
 			if (nest == NULL)
 				goto nla_put_failure;
 
-			if (tcf_action_dump(skb, exts->actions, 0, 0) < 0)
+			if (tcf_action_dump(skb, exts->actions, 0, 0, false)
+			    < 0)
 				goto nla_put_failure;
 			nla_nest_end(skb, nest);
 		} else if (exts->police) {
@@ -3203,6 +3204,31 @@ nla_put_failure:
 }
 EXPORT_SYMBOL(tcf_exts_dump);
 
+int tcf_exts_terse_dump(struct sk_buff *skb, struct tcf_exts *exts)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	struct nlattr *nest;
+
+	if (!exts->action || !tcf_exts_has_actions(exts))
+		return 0;
+
+	nest = nla_nest_start_noflag(skb, exts->action);
+	if (!nest)
+		goto nla_put_failure;
+
+	if (tcf_action_dump(skb, exts->actions, 0, 0, true) < 0)
+		goto nla_put_failure;
+	nla_nest_end(skb, nest);
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(skb, nest);
+	return -1;
+#else
+	return 0;
+#endif
+}
+EXPORT_SYMBOL(tcf_exts_terse_dump);
 
 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
 {