netdev - [PATCH 3/8] xfrmi: drop ignore_df check before updating pmtu

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Date:   Mon, 28 Sep 2020 10:24:45 +0200
From:   Steffen Klassert <steffen.klassert@...unet.com>
To:     David Miller <davem@...emloft.net>
CC:     Herbert Xu <herbert@...dor.apana.org.au>,
        Steffen Klassert <steffen.klassert@...unet.com>,
        <netdev@...r.kernel.org>
Subject: [PATCH 3/8] xfrmi: drop ignore_df check before updating pmtu

From: Sabrina Dubroca <sd@...asysnail.net>

xfrm interfaces currently test for !skb->ignore_df when deciding
whether to update the pmtu on the skb's dst. Because of this, no pmtu
exception is created when we do something like:

    ping -s 1438 <dest>

By dropping this check, the pmtu exception will be created and the
next ping attempt will work.

Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
Reported-by: Xiumei Mu <xmu@...hat.com>
Signed-off-by: Sabrina Dubroca <sd@...asysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@...unet.com>
---
 net/xfrm/xfrm_interface.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index eb8181987620..a8f66112c52b 100644
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -303,7 +303,7 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 	}
 
 	mtu = dst_mtu(dst);
-	if (!skb->ignore_df && skb->len > mtu) {
+	if (skb->len > mtu) {
 		skb_dst_update_pmtu_no_confirm(skb, mtu);
 
 		if (skb->protocol == htons(ETH_P_IPV6)) {
-- 
2.17.1