netdev - Re: [PATCH] bpf: tcp_bpf_recvmsg should return EAGAIN when nonblocking and no data

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Message-ID: <66bf62d0-45d2-8d32-d146-a06c08c88447@iogearbox.net>
Date:   Tue, 30 Oct 2018 23:30:59 +0100
From:   Daniel Borkmann <daniel@...earbox.net>
To:     John Fastabend <john.fastabend@...il.com>, ast@...nel.org
Cc:     netdev@...r.kernel.org
Subject: Re: [PATCH] bpf: tcp_bpf_recvmsg should return EAGAIN when
 nonblocking and no data

On 10/29/2018 08:31 PM, John Fastabend wrote:
> We return 0 in the case of a nonblocking socket that has no data
> available. However, this is incorrect and may confuse applications.
> After this patch we do the correct thing and return the error
> EAGAIN.
> 
> Quoting return codes from recvmsg manpage,
> 
> EAGAIN or EWOULDBLOCK
>  The socket is marked nonblocking and the receive operation would
>  block, or a receive timeout had been set and the timeout expired
>  before data was received.
> 
> Signed-off-by: John Fastabend <john.fastabend@...il.com>

Applied to bpf, thanks!