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From: Eric Biggers <ebiggers@kernel.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: netdev@vger.kernel.org, linux-crypto@vger.kernel.org,
	herbert@gondor.apana.org.au, edumazet@google.com,
	davem@davemloft.net, kuznet@ms2.inr.ac.ru,
	yoshfuji@linux-ipv6.org, jbaron@akamai.com, cpaasch@apple.com,
	David.Laight@aculab.com, ycheng@google.com
Subject: Re: [PATCH 2/2] net: fastopen: use endianness agnostic representation of the cookie
Date: Tue, 18 Jun 2019 11:22:54 -0700	[thread overview]
Message-ID: <20190618182253.GK184520@gmail.com> (raw)
In-Reply-To: <20190618093207.13436-3-ard.biesheuvel@linaro.org>

On Tue, Jun 18, 2019 at 11:32:07AM +0200, Ard Biesheuvel wrote:
> Use an explicit little endian representation of the fastopen
> cookie, so that the value no longer depends on the endianness
> of the system. This fixes a theoretical issue only, since
> fastopen keys are unlikely to be shared across load balancing
> server farms that are mixed in endiannes, but it might pop up
> in validation/selftests as well, so let's just settle on little
> endian across the board.
> 
> Note that this change only affects big endian systems.
> 
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  include/linux/tcp.h     |  2 +-
>  net/ipv4/tcp_fastopen.c | 16 ++++++++--------
>  2 files changed, 9 insertions(+), 9 deletions(-)
> 

What about the TCP_FASTOPEN_KEY option for setsockopt and getsockopt?  Those
APIs treat the key as an array of bytes (let's say it's little endian), so
doesn't it need to be converted to/from the CPU endianness of siphash_key_t?

- Eric

  reply	other threads:[~2019-06-18 18:22 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-18  9:32 [PATCH 0/2] net: fastopen: follow-up tweaks for SipHash switch Ard Biesheuvel
2019-06-18  9:32 ` [PATCH 1/2] net: fastopen: make key handling more robust against future changes Ard Biesheuvel
2019-06-18  9:39   ` Eric Dumazet
2019-06-18  9:41     ` Ard Biesheuvel
2019-06-18  9:53       ` Eric Dumazet
2019-06-18 10:02         ` Ard Biesheuvel
2019-06-18 18:18         ` Eric Biggers
2019-06-18 18:19           ` Eric Dumazet
2019-06-18  9:32 ` [PATCH 2/2] net: fastopen: use endianness agnostic representation of the cookie Ard Biesheuvel
2019-06-18 18:22   ` Eric Biggers [this message]
2019-06-18 18:40     ` Ard Biesheuvel
2019-06-18 22:40       ` David Miller
2019-06-18  9:37 ` [PATCH 0/2] net: fastopen: follow-up tweaks for SipHash switch Eric Dumazet
2019-06-18  9:38   ` Ard Biesheuvel

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