Re: ixgbe: driver drops packets routed from an IPSec interface with a "bad sa_idx" error

[Michael Marley <michael@michaelmarley.com>]

On 2019-09-11 02:15, Steffen Klassert wrote:
> On Tue, Sep 10, 2019 at 06:53:30PM -0400, Michael Marley wrote:
>> 
>> StrongSwan has hardware offload disabled by default, and I didn't 
>> enable
>> it explicitly.  I also already tried turning off all those switches 
>> with
>> ethtool and it has no effect.  This doesn't surprise me though, 
>> because
>> as I said, I don't actually have the IPSec connection running over the
>> ixgbe device.  The IPSec connection runs over another network adapter
>> that doesn't support IPSec offload at all.  The problem comes when
>> traffic received over the IPSec interface is then routed back out
>> (unencrypted) through the ixgbe device into the local network.
> 
> 
> Seems like the ixgbe driver tries to use the sec_path
> from RX to setup an offload at the TX side.
> 
> Can you please try this (completely untested) patch?
> 
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> index 9bcae44e9883..ae31bd57127c 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> @@ -36,6 +36,7 @@
>  #include <net/vxlan.h>
>  #include <net/mpls.h>
>  #include <net/xdp_sock.h>
> +#include <net/xfrm.h>
> 
>  #include "ixgbe.h"
>  #include "ixgbe_common.h"
> @@ -8696,7 +8697,7 @@ netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff 
> *skb,
>  #endif /* IXGBE_FCOE */
> 
>  #ifdef CONFIG_IXGBE_IPSEC
> -	if (secpath_exists(skb) &&
> +	if (xfrm_offload(skb) &&
>  	    !ixgbe_ipsec_tx(tx_ring, first, &ipsec_tx))
>  		goto out_drop;
>  #endif
With the patch, the problem is gone.  Thanks!

Michael