Re: [dpdk-dev] [PATCH] gro: fix an error when packet is IPv6

["Hu, Jiayu" <jiayu.hu@intel.com>]

Hi Yi,

> -----Original Message-----
> From: yang_y_yi@163.com <yang_y_yi@163.com>
> Sent: Wednesday, November 4, 2020 12:23 PM
> To: dev@dpdk.org
> Cc: Hu, Jiayu <jiayu.hu@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; thomas@monjalon.net;
> yangyi01@inspur.com; yang_y_yi@163.com
> Subject: [PATCH] gro: fix an error when packet is IPv6
> 
> From: Yi Yang <yangyi01@inspur.com>
> 
> Current code will think IPv6 packet as IPv4 packet
> if inner header is IPv6 and outer header is IPv4,
> the result is rte_gro_reassemble() will handle it
> as if inner header also is IPv4, so IPv6 can't
> be handled correctly as one of unprocess_pkts.

Good catch. If the input is a VxLAN pkt whose inner
L3 is IPv6, inner L4 is TCP or UDP, and outer L3 is IPv4,
the value of IS_IPV4_VXLAN_TCP4/UDP4_PKT is true.
Thus, GRO will mistakenly reassemble it.

But for  IS_IPV4_UDP/TCP_PKT, I think it's better to use
"RTE_ETH_IS_TUNNEL_PKT(ptype) == 0", rather than
"((ptype & RTE_PTYPE_TUNNEL_VXLAN) == 0".

BTW, the commit log is not easy to understand what
bug the patch tries to fix.

Thanks,
Jiayu

> 
> Fixes: e2d811063673 ("gro: support VXLAN UDP/IPv4")
> Fixes: 1ca5e6740852 ("gro: support UDP/IPv4")
> Fixes: 9e0b9d2ec0f4 ("gro: support VxLAN GRO")
> Fixes: 0d2cbe59b719 ("lib/gro: support TCP/IPv4")
> Signed-off-by: Yi Yang <yangyi01@inspur.com>
> ---
>  lib/librte_gro/rte_gro.c | 34 ++++++++++++++++++++--------------
>  1 file changed, 20 insertions(+), 14 deletions(-)
> 
> diff --git a/lib/librte_gro/rte_gro.c b/lib/librte_gro/rte_gro.c
> index e56bd20..4347267 100644
> --- a/lib/librte_gro/rte_gro.c
> +++ b/lib/librte_gro/rte_gro.c
> @@ -32,32 +32,38 @@
>  			NULL};
> 
>  #define IS_IPV4_TCP_PKT(ptype) (RTE_ETH_IS_IPV4_HDR(ptype) && \
> -		((ptype & RTE_PTYPE_L4_TCP) == RTE_PTYPE_L4_TCP))
> +		((ptype & RTE_PTYPE_L4_TCP) == RTE_PTYPE_L4_TCP) && \
> +		((ptype & RTE_PTYPE_TUNNEL_VXLAN) == 0))
> 
>  #define IS_IPV4_UDP_PKT(ptype) (RTE_ETH_IS_IPV4_HDR(ptype) && \
> -		((ptype & RTE_PTYPE_L4_UDP) == RTE_PTYPE_L4_UDP))
> +		((ptype & RTE_PTYPE_L4_UDP) == RTE_PTYPE_L4_UDP) && \
> +		((ptype & RTE_PTYPE_TUNNEL_VXLAN) == 0))
> 
>  #define IS_IPV4_VXLAN_TCP4_PKT(ptype) (RTE_ETH_IS_IPV4_HDR(ptype)
> && \
>  		((ptype & RTE_PTYPE_L4_UDP) == RTE_PTYPE_L4_UDP) && \
>  		((ptype & RTE_PTYPE_TUNNEL_VXLAN) == \
>  		 RTE_PTYPE_TUNNEL_VXLAN) && \
> -		 ((ptype & RTE_PTYPE_INNER_L4_TCP) == \
> -		  RTE_PTYPE_INNER_L4_TCP) && \
> -		  (((ptype & RTE_PTYPE_INNER_L3_MASK) & \
> -		    (RTE_PTYPE_INNER_L3_IPV4 | \
> -		     RTE_PTYPE_INNER_L3_IPV4_EXT | \
> -		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN)) != 0))
> +		((ptype & RTE_PTYPE_INNER_L4_TCP) == \
> +		 RTE_PTYPE_INNER_L4_TCP) && \
> +		(((ptype & RTE_PTYPE_INNER_L3_MASK) == \
> +		  RTE_PTYPE_INNER_L3_IPV4) || \
> +		 ((ptype & RTE_PTYPE_INNER_L3_MASK) == \
> +		  RTE_PTYPE_INNER_L3_IPV4_EXT) || \
> +		 ((ptype & RTE_PTYPE_INNER_L3_MASK) == \
> +		  RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN)))
> 
>  #define IS_IPV4_VXLAN_UDP4_PKT(ptype) (RTE_ETH_IS_IPV4_HDR(ptype)
> && \
>  		((ptype & RTE_PTYPE_L4_UDP) == RTE_PTYPE_L4_UDP) && \
>  		((ptype & RTE_PTYPE_TUNNEL_VXLAN) == \
>  		 RTE_PTYPE_TUNNEL_VXLAN) && \
> -		 ((ptype & RTE_PTYPE_INNER_L4_UDP) == \
> -		  RTE_PTYPE_INNER_L4_UDP) && \
> -		  (((ptype & RTE_PTYPE_INNER_L3_MASK) & \
> -		    (RTE_PTYPE_INNER_L3_IPV4 | \
> -		     RTE_PTYPE_INNER_L3_IPV4_EXT | \
> -		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN)) != 0))
> +		((ptype & RTE_PTYPE_INNER_L4_UDP) == \
> +		 RTE_PTYPE_INNER_L4_UDP) && \
> +		(((ptype & RTE_PTYPE_INNER_L3_MASK) == \
> +		  RTE_PTYPE_INNER_L3_IPV4) || \
> +		 ((ptype & RTE_PTYPE_INNER_L3_MASK) == \
> +		  RTE_PTYPE_INNER_L3_IPV4_EXT) || \
> +		 ((ptype & RTE_PTYPE_INNER_L3_MASK) == \
> +		  RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN)))
> 
>  /*
>   * GRO context structure. It keeps the table structures, which are
> --
> 1.8.3.1