Subject: [PATCH 27/27] vrf: Check skb for XFRM_TRANSFORMED flag

From: David Ahern <[email-masked]>
Date: Mon, 20 Apr 2020 17:13:52 -0600

[ Upstream commit 16b9db1ce34ff00d6c18e82825125cfef0cdfb13 ]

To avoid a loop with qdiscs and xfrms, check if the skb has already gone
through the qdisc attached to the VRF device and then to the xfrm layer.
If so, no need for a second redirect.

Fixes: 193125dbd8eb ("net: Introduce VRF device driver")
Reported-by: Trev Larock <[email-masked]>
Signed-off-by: David Ahern <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/vrf.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 4285236b5f2e..6716deeb35e3 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -474,7 +474,8 @@ static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
 	if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
 		return skb;
 
-	if (qdisc_tx_is_default(vrf_dev))
+	if (qdisc_tx_is_default(vrf_dev) ||
+	    IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
 		return vrf_ip6_out_direct(vrf_dev, sk, skb);
 
 	return vrf_ip6_out_redirect(vrf_dev, skb);
@@ -686,7 +687,8 @@ static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
 	    ipv4_is_lbcast(ip_hdr(skb)->daddr))
 		return skb;
 
-	if (qdisc_tx_is_default(vrf_dev))
+	if (qdisc_tx_is_default(vrf_dev) ||
+	    IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
 		return vrf_ip_out_direct(vrf_dev, sk, skb);
 
 	return vrf_ip_out_redirect(vrf_dev, skb);
-- 
2.20.1