From: Davide Caratti <dcaratti@redhat.com>
Date: Wed, 19 May 2021 13:17:21 +0000 (+0200)
Subject: net/sched: cls_api: increase max_reclassify_loop
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=05ff8435e50569a0a6b95e5ceaea43696e8827ab;p=linux.git

net/sched: cls_api: increase max_reclassify_loop

modern userspace applications, like OVN, can configure the TC datapath to
"recirculate" packets several times. If more than 4 "recirculation" rules
are configured, packets can be dropped by __tcf_classify().
Changing the maximum number of reclassifications (from 4 to 16) should be
sufficient to prevent drops in most use cases, and guard against loops at
the same time.

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 40fbea626dfd2..75e3a288a7c88 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1531,7 +1531,7 @@ static inline int __tcf_classify(struct sk_buff *skb,
 				 u32 *last_executed_chain)
 {
 #ifdef CONFIG_NET_CLS_ACT
-	const int max_reclassify_loop = 4;
+	const int max_reclassify_loop = 16;
 	const struct tcf_proto *first_tp;
 	int limit = 0;