From: David Ahern <dsahern@gmail.com>
To: Jakub Kicinski <kuba@kernel.org>, Arjun Roy <arjunroy.kdev@gmail.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org, arjunroy@google.com,
edumazet@google.com, soheil@google.com
Subject: Re: [net-next v2 2/2] tcp: Add receive timestamp support for receive zerocopy.
Date: Fri, 22 Jan 2021 22:55:45 -0700 [thread overview]
Message-ID: <a18cbf73-1720-dec0-fbc6-2e357fee6bd8@gmail.com> (raw)
In-Reply-To: <20210122200723.50e4afe6@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
On 1/22/21 9:07 PM, Jakub Kicinski wrote:
> On Wed, 20 Jan 2021 16:41:48 -0800 Arjun Roy wrote:
>> diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
>> index 768e93bd5b51..b216270105af 100644
>> --- a/include/uapi/linux/tcp.h
>> +++ b/include/uapi/linux/tcp.h
>> @@ -353,5 +353,9 @@ struct tcp_zerocopy_receive {
>> __u64 copybuf_address; /* in: copybuf address (small reads) */
>> __s32 copybuf_len; /* in/out: copybuf bytes avail/used or error */
>> __u32 flags; /* in: flags */
>> + __u64 msg_control; /* ancillary data */
>> + __u64 msg_controllen;
>> + __u32 msg_flags;
>> + /* __u32 hole; Next we must add >1 u32 otherwise length checks fail. */
>
> Well, let's hope nobody steps on this landmine.. :)
>
Past suggestions were made to use anonymous declarations - e.g., __u32
:32; - as a way of reserving the space for future use. That or declare
'__u32 resvd', check that it must be 0 and makes it available for later
(either directly or with a union).
next prev parent reply other threads:[~2021-01-23 5:59 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 0:41 [net-next v2 0/2] tcp: add CMSG+rx timestamps to rx. zerocopy Arjun Roy
2021-01-21 0:41 ` [net-next v2 1/2] tcp: Remove CMSG magic numbers for tcp_recvmsg() Arjun Roy
2021-01-21 0:41 ` [net-next v2 2/2] tcp: Add receive timestamp support for receive zerocopy Arjun Roy
2021-01-23 4:07 ` Jakub Kicinski
2021-01-23 5:55 ` David Ahern [this message]
2021-01-25 6:15 ` Leon Romanovsky
2021-02-02 2:06 ` David Ahern
2021-02-02 2:20 ` Arjun Roy
2021-02-02 6:52 ` Leon Romanovsky
2021-02-04 23:03 ` Arjun Roy
2021-02-05 0:00 ` Jakub Kicinski
2021-02-05 1:32 ` Arjun Roy
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