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From: Maxim Mikityanskiy <maximmi@nvidia.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Lorenz Bauer" <lmb@cloudflare.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>, Eric Dumazet <edumazet@google.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	David Ahern <dsahern@kernel.org>,
	"Jesper Dangaard Brouer" <hawk@kernel.org>,
	Nathan Chancellor <nathan@kernel.org>,
	"Nick Desaulniers" <ndesaulniers@google.com>,
	Brendan Jackman <jackmanb@google.com>,
	Florent Revest <revest@chromium.org>,
	Joe Stringer <joe@cilium.io>, Tariq Toukan <tariqt@nvidia.com>,
	Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
	<clang-built-linux@googlegroups.com>
Subject: Re: [PATCH bpf-next 09/10] bpf: Add a helper to issue timestamp cookies in XDP
Date: Fri, 22 Oct 2021 19:56:06 +0300	[thread overview]
Message-ID: <533129a4-7f4e-e7a6-407c-f15b6acbb0e2@nvidia.com> (raw)
In-Reply-To: <87y26nekoc.fsf@toke.dk>

On 2021-10-20 19:16, Toke Høiland-Jørgensen wrote:
> Lorenz Bauer <lmb@cloudflare.com> writes:
> 
>>> +bool cookie_init_timestamp_raw(struct tcphdr *th, __be32 *tsval, __be32 *tsecr)
>>
>> I'm probably missing context, Is there something in this function that
>> means you can't implement it in BPF?
> 
> I was about to reply with some other comments but upon closer inspection
> I ended up at the same conclusion: this helper doesn't seem to be needed
> at all?

tcp_time_stamp_raw() uses ktime_get_ns(), while bpf_ktime_get_ns() uses 
ktime_get_mono_fast_ns(). Is it fine to use ktime_get_mono_fast_ns() 
instead of ktime_get_ns()? I'm a bit worried about this note in 
Documentation/core-api/timekeeping.rst:

 > most drivers should never call them,
 > since the time is allowed to jump under certain conditions.

  reply	other threads:[~2021-10-22 16:56 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-19 14:46 [PATCH bpf-next 00/10] New BPF helpers to accelerate synproxy Maxim Mikityanskiy
2021-10-19 14:46 ` [PATCH bpf-next 01/10] bpf: Use ipv6_only_sock in bpf_tcp_gen_syncookie Maxim Mikityanskiy
2021-10-19 14:46 ` [PATCH bpf-next 02/10] bpf: Support dual-stack sockets in bpf_tcp_check_syncookie Maxim Mikityanskiy
2021-10-19 14:46 ` [PATCH bpf-next 03/10] bpf: Use EOPNOTSUPP " Maxim Mikityanskiy
2021-10-19 14:46 ` [PATCH bpf-next 04/10] bpf: Make errors of bpf_tcp_check_syncookie distinguishable Maxim Mikityanskiy
2021-10-20  3:28   ` John Fastabend
2021-10-20 13:16     ` Maxim Mikityanskiy
2021-10-20 15:26       ` Lorenz Bauer
2021-10-19 14:46 ` [PATCH bpf-next 05/10] bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie Maxim Mikityanskiy
2021-10-19 14:46 ` [PATCH bpf-next 06/10] bpf: Expose struct nf_conn to BPF Maxim Mikityanskiy
2021-10-19 14:46 ` [PATCH bpf-next 07/10] bpf: Add helpers to query conntrack info Maxim Mikityanskiy
2021-10-20  3:56   ` Kumar Kartikeya Dwivedi
2021-10-20  9:28     ` Florian Westphal
2021-10-20  9:48       ` Toke Høiland-Jørgensen
2021-10-20  9:58         ` Florian Westphal
2021-10-20 12:21           ` Toke Høiland-Jørgensen
2021-10-20 12:44             ` Florian Westphal
2021-10-20 20:54               ` Toke Høiland-Jørgensen
2021-10-20 22:55                 ` David Ahern
2021-10-21  7:36                 ` Florian Westphal
2021-10-20 13:18     ` Maxim Mikityanskiy
2021-10-20 19:17       ` Kumar Kartikeya Dwivedi
2021-10-20  9:46   ` Toke Høiland-Jørgensen
2021-10-19 14:46 ` [PATCH bpf-next 08/10] bpf: Add helpers to issue and check SYN cookies in XDP Maxim Mikityanskiy
2021-10-19 14:46 ` [PATCH bpf-next 09/10] bpf: Add a helper to issue timestamp " Maxim Mikityanskiy
2021-10-19 16:45   ` Eric Dumazet
2021-10-20 13:16     ` Maxim Mikityanskiy
2021-10-20 15:56   ` Lorenz Bauer
2021-10-20 16:16     ` Toke Høiland-Jørgensen
2021-10-22 16:56       ` Maxim Mikityanskiy [this message]
2021-10-27  8:34         ` Lorenz Bauer
2021-11-01 11:14       ` Maxim Mikityanskiy
2021-11-03  2:10         ` Yonghong Song
2021-11-03 14:02           ` Maxim Mikityanskiy
2021-11-09  7:11             ` Yonghong Song
2021-11-25 14:34               ` Maxim Mikityanskiy
2021-11-26  5:43                 ` Yonghong Song
2021-11-26 16:50                   ` Maxim Mikityanskiy
2021-11-26 17:07                     ` Yonghong Song
2021-11-29 17:51                       ` Maxim Mikityanskiy
2021-12-01  6:39                         ` Yonghong Song
2021-12-01 18:06                           ` Andrii Nakryiko
2021-10-19 14:46 ` [PATCH bpf-next 10/10] bpf: Add sample for raw syncookie helpers Maxim Mikityanskiy
2021-10-20 18:01   ` Joe Stringer
2021-10-21 17:19     ` Maxim Mikityanskiy
2021-10-21  1:06   ` Alexei Starovoitov
2021-10-21 17:31     ` Maxim Mikityanskiy
2021-10-21 18:50       ` Alexei Starovoitov

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