netdev - [PATCH v1 net-next] ipv6: rpl: Remove redundant skb_dst

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Date: Mon, 10 Jul 2023 14:35:11 -0700
From: Kuniyuki Iwashima <kuniyu@...zon.com>
To: "David S. Miller" <davem@...emloft.net>, David Ahern <dsahern@...nel.org>,
	Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, "Paolo
 Abeni" <pabeni@...hat.com>
CC: Kuniyuki Iwashima <kuniyu@...zon.com>, Kuniyuki Iwashima
	<kuni1840@...il.com>, <netdev@...r.kernel.org>
Subject: [PATCH v1 net-next] ipv6: rpl: Remove redundant skb_dst_drop().

RPL code has a pattern where skb_dst_drop() is called before
ip6_route_input().

However, ip6_route_input() calls skb_dst_drop() internally,
so we need not call skb_dst_drop() before ip6_route_input().

Signed-off-by: Kuniyuki Iwashima <kuniyu@...zon.com>
---
 net/ipv6/exthdrs.c      | 2 --
 net/ipv6/rpl_iptunnel.c | 3 +--
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 202fc3aaa83c..f4bfccae003c 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -612,8 +612,6 @@ static int ipv6_rpl_srh_rcv(struct sk_buff *skb)
 
 	kfree(buf);
 
-	skb_dst_drop(skb);
-
 	ip6_route_input(skb);
 
 	if (skb_dst(skb)->error) {
diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c
index b1c028df686e..a013b92cbb86 100644
--- a/net/ipv6/rpl_iptunnel.c
+++ b/net/ipv6/rpl_iptunnel.c
@@ -272,8 +272,6 @@ static int rpl_input(struct sk_buff *skb)
 	dst = dst_cache_get(&rlwt->cache);
 	preempt_enable();
 
-	skb_dst_drop(skb);
-
 	if (!dst) {
 		ip6_route_input(skb);
 		dst = skb_dst(skb);
@@ -284,6 +282,7 @@ static int rpl_input(struct sk_buff *skb)
 			preempt_enable();
 		}
 	} else {
+		skb_dst_drop(skb);
 		skb_dst_set(skb, dst);
 	}
 
-- 
2.30.2