[ovs-dev] [PATCH] dpif: Ensure ERSPAN GRE support

[Eric Garver]

I'm a bit late, but I have comments below.

I'm also a bit out of touch, so I may be missing some context - if so, I
apologize.

On Thu, May 31, 2018 at 03:50:31PM -0700, Greg Rose wrote:
> When verifying the built-in gre kernel module check for ERSPAN support.
> 
> Reported-by: Guru Shetty <guru at ovn.org>
> Signed-off-by: Greg Rose <gvrose8192 at gmail.com>
> ---
>  lib/dpif-netlink-rtnl.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/dpif-netlink-rtnl.c b/lib/dpif-netlink-rtnl.c
> index bec3fce..197cfb6 100644
> --- a/lib/dpif-netlink-rtnl.c
> +++ b/lib/dpif-netlink-rtnl.c
> @@ -45,8 +45,8 @@ VLOG_DEFINE_THIS_MODULE(dpif_netlink_rtnl);
>  #ifndef IFLA_GRE_MAX
>  #define IFLA_GRE_MAX 0
>  #endif
> -#if IFLA_GRE_MAX < 18
> -#define IFLA_GRE_COLLECT_METADATA 18
> +#if IFLA_GRE_MAX < 24
> +#define IFLA_GRE_ERSPAN_HWID 24
>  #endif
>  
>  #ifndef IFLA_GENEVE_MAX
> @@ -74,7 +74,7 @@ static const struct nl_policy vxlan_policy[] = {
>      [IFLA_VXLAN_GPE] = { .type = NL_A_FLAG, .optional = true },
>  };
>  static const struct nl_policy gre_policy[] = {
> -    [IFLA_GRE_COLLECT_METADATA] = { .type = NL_A_FLAG },

I think we still need to verify _COLLECT_METADATA was passed back.

> +    [IFLA_GRE_ERSPAN_HWID] = { .type = NL_A_U16 },
>  };
>  static const struct nl_policy geneve_policy[] = {
>      [IFLA_GENEVE_COLLECT_METADATA] = { .type = NL_A_FLAG },
> @@ -207,7 +207,7 @@ dpif_netlink_rtnl_gre_verify(const struct netdev_tunnel_config OVS_UNUSED *tnl,
>      err = rtnl_policy_parse(kind, reply, gre_policy, gre,
>                              ARRAY_SIZE(gre_policy));
>      if (!err) {
> -        if (!nl_attr_get_flag(gre[IFLA_GRE_COLLECT_METADATA])) {
> +        if (!nl_attr_get_u16(gre[IFLA_GRE_ERSPAN_HWID])) {

We need to verify COLLECT_METADATA is actually in use here. We should
only be checking for ERSPAN if ERSPAN was requested by the user.

>              err = EINVAL;
>          }
>      }
> @@ -328,7 +328,7 @@ dpif_netlink_rtnl_create(const struct netdev_tunnel_config *tnl_cfg,
>      case OVS_VPORT_TYPE_ERSPAN:
>      case OVS_VPORT_TYPE_IP6ERSPAN:
>      case OVS_VPORT_TYPE_IP6GRE:
> -        nl_msg_put_flag(&request, IFLA_GRE_COLLECT_METADATA);

I think we still need to use COLLECT_METADATA. Don't we depend on using
lwt?

> +        nl_msg_put_u16(&request, IFLA_GRE_ERSPAN_HWID, 0xdead);
>          break;
>      case OVS_VPORT_TYPE_GENEVE:
>          nl_msg_put_flag(&request, IFLA_GENEVE_COLLECT_METADATA);