Re: [PATCH v5 net-next 5/7] ip6tlvs: Add TX parameters

[Simon Horman <simon.horman@netronome.com>]

On Thu, Oct 03, 2019 at 02:58:02PM -0700, Tom Herbert wrote:
> From: Tom Herbert <tom@quantonium.net>
> 
> Define a number of transmit parameters for TLV Parameter table
> definitions. These will be used for validating TLVs that are set
> on a socket.
> 
> Signed-off-by: Tom Herbert <tom@herbertland.com>
> ---
>  include/net/ipeh.h         | 18 ++++++++++++++++
>  include/uapi/linux/ipeh.h  |  8 +++++++
>  net/ipv6/exthdrs_common.c  | 53 +++++++++++++++++++++++++++++++++++++++++++++-
>  net/ipv6/exthdrs_options.c | 45 +++++++++++++++++++++++++++++++++++++++
>  4 files changed, 123 insertions(+), 1 deletion(-)
> 
> diff --git a/include/net/ipeh.h b/include/net/ipeh.h
> index aaa2910..de6d9d0 100644
> --- a/include/net/ipeh.h
> +++ b/include/net/ipeh.h

...

> @@ -54,6 +65,13 @@ struct tlv_param_table {
>  
>  extern struct tlv_param_table ipv6_tlv_param_table;
>  
> +/* Preferred TLV ordering for HBH and Dest options (placed by increasing order)
> + */
> +#define IPEH_TLV_PREF_ORDER_HAO			10
> +#define IPEH_TLV_PREF_ORDER_ROUTERALERT		20
> +#define IPEH_TLV_PREF_ORDER_JUMBO		30
> +#define IPEH_TLV_PREF_ORDER_CALIPSO		40
> +

Hi Tom,

Could you expand on why thse values were chosen?

I can see that this patch implements a specific use of
the 255 indexes available. But its not at all clear to me that
this use fits expected use-cases (because I don't know what they are).

...