xfrm: Fix double ESP trailer insertion in IPsec crypto offload.

During IPsec performance testing, we see bad ICMP checksum. The error packet
has duplicated ESP trailer due to double validate_xmit_xfrm calls. The first call
is from ip_output, but the packet cannot be sent because
netif_xmit_frozen_or_stopped is true and the packet gets dev_requeue_skb. The second
call is from NET_TX softirq. However after the first call, the packet already
has the ESP trailer.

Fix by marking the skb with XFRM_XMIT bit after the packet is handled by
validate_xmit_xfrm to avoid duplicate ESP trailer insertion.

Fixes: f6e27114a60a ("net: Add a xfrm validate function to validate_xmit_skb")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Boris Pismenny <borisp@mellanox.com>
Reviewed-by: Raed Salem <raeds@mellanox.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 094fe68..c7d213c 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1008,6 +1008,7 @@ struct xfrm_offload {
 #define        XFRM_GRO                32
 #define        XFRM_ESP_NO_TRAILER     64
 #define        XFRM_DEV_RESUME         128
+#define        XFRM_XMIT               256
 
        __u32                   status;
 #define CRYPTO_SUCCESS                         1

diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index f50d1f9..626096b 100644 (file)
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -108,7 +108,7 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
        struct xfrm_offload *xo = xfrm_offload(skb);
        struct sec_path *sp;
 
-       if (!xo)
+       if (!xo || (xo->flags & XFRM_XMIT))
                return skb;
 
        if (!(features & NETIF_F_HW_ESP))
@@ -129,6 +129,8 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
                return skb;
        }
 
+       xo->flags |= XFRM_XMIT;
+
        if (skb_is_gso(skb)) {
                struct net_device *dev = skb->dev;