ipsec through openvpn broken

ipsec through openvpn broken

[Artem Savkov]

Hi Yossi, Steffen,

I am using ipsec throug openvpn on one of my machines and it stopped
working since 4.15. Bisection showed that the culprit is:
5efec5c655dd xfrm: Fix eth_hdr(skb)->h_proto to reflect inner IP version

Reverting the patch does fix it for me.

I am seing h_proto being changed from 0x1bac to 0x8 and wireshark
doesn't see the ethernet header anymore:

Packet sent:

Frame 3: 142 bytes on wire (1136 bits), 142 bytes captured (1136 bits)
Ethernet II, Src: xx:xx:xx:xx:52:01 (xx:xx:xx:xx:52:01), Dst: IETF-VRRP-VRID_6a (xx:xx:xx:xx:01:6a)
Internet Protocol Version 4, Src: xx.xx.xx.xx, Dst: yy.yy.yy.yy
User Datagram Protocol, Src Port: 4500, Dst Port: 4500
UDP Encapsulation of IPsec Packets
Encapsulating Security Payload
    ESP SPI: 0xc4bbc7d8 (3300640728)
    ESP Sequence: 29


Packet received:

Frame 6: 128 bytes on wire (1024 bits), 128 bytes captured (1024 bits)
Raw packet data
Internet Protocol Version 4, Src: xx.xx.xx.xx, Dst: zz.zz.zz.zz
User Datagram Protocol, Src Port: 4500, Dst Port: 4500
UDP Encapsulation of IPsec Packets
Encapsulating Security Payload
    ESP SPI: 0xc4bbc7d8 (3300640728)
    ESP Sequence: 29

-- 
Regards,
  Artem Savkov

RE: ipsec through openvpn broken

[Yossi Kuperman]

> -----Original Message-----
> From: Artem Savkov [mailto:artem.savkov@gmail.com]
> Sent: Sunday, February 11, 2018 10:34 AM
> To: Yossi Kuperman <yossiku@mellanox.com>; Steffen Klassert <steffen.klassert@secunet.com>
> Cc: netdev@vger.kernel.org
> Subject: ipsec through openvpn broken
> 
> Hi Yossi, Steffen,
> 
> I am using ipsec throug openvpn on one of my machines and it stopped

I was trying to reproduce it and install OpenVPN, but according to their website,
it doesn’t support IPSec?

> working since 4.15. Bisection showed that the culprit is:
> 5efec5c655dd xfrm: Fix eth_hdr(skb)->h_proto to reflect inner IP version
> 
> Reverting the patch does fix it for me.
> 
> I am seing h_proto being changed from 0x1bac to 0x8 and wireshark
> doesn't see the ethernet header anymore:
> 
> Packet sent:
> 

Can you please share the entire packet hex dump (sent and received)? 
Not sure what 0x1bac should represent.

> Frame 3: 142 bytes on wire (1136 bits), 142 bytes captured (1136 bits)
> Ethernet II, Src: xx:xx:xx:xx:52:01 (xx:xx:xx:xx:52:01), Dst: IETF-VRRP-VRID_6a (xx:xx:xx:xx:01:6a)
> Internet Protocol Version 4, Src: xx.xx.xx.xx, Dst: yy.yy.yy.yy
> User Datagram Protocol, Src Port: 4500, Dst Port: 4500
> UDP Encapsulation of IPsec Packets
> Encapsulating Security Payload
>     ESP SPI: 0xc4bbc7d8 (3300640728)
>     ESP Sequence: 29
> 
> 
> Packet received:
> 
> Frame 6: 128 bytes on wire (1024 bits), 128 bytes captured (1024 bits)
> Raw packet data
> Internet Protocol Version 4, Src: xx.xx.xx.xx, Dst: zz.zz.zz.zz
> User Datagram Protocol, Src Port: 4500, Dst Port: 4500
> UDP Encapsulation of IPsec Packets
> Encapsulating Security Payload
>     ESP SPI: 0xc4bbc7d8 (3300640728)
>     ESP Sequence: 29
> 
> --
> Regards,
>   Artem Savkov