netdev - [iproute PATCH] tc: Optimize gact action lookup

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Date:   Fri, 12 Jan 2018 12:20:21 +0100
From:   Phil Sutter <phil@....cc>
To:     Stephen Hemminger <stephen@...workplumber.org>
Cc:     netdev@...r.kernel.org, Jiri Pirko <jiri@...lanox.com>,
        Jamal Hadi Salim <jhs@...atatu.com>,
        David Ahern <dsahern@...il.com>
Subject: [iproute PATCH] tc: Optimize gact action lookup

When adding a filter with a gact action such as 'drop', tc first tries
to open a shared object with equivalent name (m_drop.so in this case)
before trying gact. Avoid this by matching the action name against those
handled by gact prior to calling get_action_kind().

Cc: Jiri Pirko <jiri@...lanox.com>
Cc: Jamal Hadi Salim <jhs@...atatu.com>
Cc: David Ahern <dsahern@...il.com>
Signed-off-by: Phil Sutter <phil@....cc>
---
 tc/m_action.c |  5 ++++-
 tc/tc_util.c  | 10 ++++++----
 tc/tc_util.h  |  2 ++
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/tc/m_action.c b/tc/m_action.c
index fc4223648e8cf..d3df93c066a89 100644
--- a/tc/m_action.c
+++ b/tc/m_action.c
@@ -194,7 +194,10 @@ int parse_action(int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n)
 		} else {
 			struct action_util *a = NULL;
 
-			strncpy(k, *argv, sizeof(k) - 1);
+			if (!action_a2n(*argv, NULL, false))
+				strncpy(k, "gact", sizeof(k) - 1);
+			else
+				strncpy(k, *argv, sizeof(k) - 1);
 			eap = 0;
 			if (argc > 0) {
 				a = get_action_kind(k);
diff --git a/tc/tc_util.c b/tc/tc_util.c
index ee9a70aa6830c..10e5aa91168a1 100644
--- a/tc/tc_util.c
+++ b/tc/tc_util.c
@@ -511,7 +511,7 @@ static const char *action_n2a(int action)
  *
  * In error case, returns -1 and does not touch @result. Otherwise returns 0.
  */
-static int action_a2n(char *arg, int *result, bool allow_num)
+int action_a2n(char *arg, int *result, bool allow_num)
 {
 	int n;
 	char dummy;
@@ -535,13 +535,15 @@ static int action_a2n(char *arg, int *result, bool allow_num)
 	for (iter = a2n; iter->a; iter++) {
 		if (matches(arg, iter->a) != 0)
 			continue;
-		*result = iter->n;
-		return 0;
+		n = iter->n;
+		goto out_ok;
 	}
 	if (!allow_num || sscanf(arg, "%d%c", &n, &dummy) != 1)
 		return -1;
 
-	*result = n;
+out_ok:
+	if (result)
+		*result = n;
 	return 0;
 }
 
diff --git a/tc/tc_util.h b/tc/tc_util.h
index 1218610d77092..e354765ff1ed0 100644
--- a/tc/tc_util.h
+++ b/tc/tc_util.h
@@ -132,4 +132,6 @@ int prio_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt);
 int cls_names_init(char *path);
 void cls_names_uninit(void);
 
+int action_a2n(char *arg, int *result, bool allow_num);
+
 #endif
-- 
2.15.1