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Subject: Re: recvmsg() "short receive" after FIONREAD
From: Andriy Gapon <avg@FreeBSD.org>
To: Mark Johnston <markj@freebsd.org>
Cc: "net@FreeBSD.org" <net@freebsd.org>, hackers@freebsd.org
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On 10/09/2021 22:40, Andriy Gapon wrote:
> On 10/09/2021 22:38, Andriy Gapon wrote:
>> On 10/09/2021 22:35, Mark Johnston wrote:
>>> Indeed, I suspect that this is the problem.  Note that for
>>> kevent(EVFILT_READ) we subtract the number of control message bytes from
>>> the returned value, see filt_soread().  I wonder if FIONREAD should do
>>> the same thing.
>>
>> Thank you for the suggestion.
>> I think that it is a reasonable expectation that FIONREAD returns a number of 
>> bytes that can be actually read.
>> I'll look at filt_soread().
> 
> kn_data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
> Is this it?
> Looks simple enough for a quick test :)


Works perfectly.
Should I just commit it or is a larger discussion needed?

-- 
Andriy Gapon