From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH] net: implement IP_RECVHDRS option to get full headers
 through recvmsg cmsg.
Date: Sat, 31 Mar 2018 23:51:06 -0700
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References: <20180401054314.33578-1-zenczykowski@gmail.com>
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Cc: netdev@vger.kernel.org, Luigi Rizzo <lrizzo@google.com>,
        Eric Dumazet <edumazet@google.com>
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        =?UTF-8?Q?Maciej_=c5=bbenczykowski?= <maze@google.com>,
        "David S . Miller" <davem@davemloft.net>
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On 03/31/2018 10:43 PM, Maciej Żenczykowski wrote:
> From: Luigi Rizzo <lrizzo@google.com>
> 
> We have all sorts of different ways to fetch pre-UDP payload metadata:
>   IP_RECVTOS
>   IP_RECVTTL
>   IP_RECVOPTS
>   IP_RETOPTS
> 
> But nothing generic which simply allows you to receive the entire packet header.
> 
> This is in similar vein to TCP_SAVE_SYN but for UDP and other datagram sockets.
> 
> This is envisioned as a way to get GUE extension metadata for encapsulated
> packets, but implemented in a way to be much more future proof.
> 
> (Implemented by Luigi, who asked me to send it upstream)
> 

Hmm... what happened to IPv6 ? ;)