netdev - SO_LINGER dead: I get an immediate RST on 2.6.24?

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Message-ID: <20090111212303.GA8612@outpost.ds9a.nl>
Date:	Sun, 11 Jan 2009 22:23:03 +0100
From:	bert hubert <bert.hubert@...herlabs.nl>
To:	netdev@...r.kernel.org
Subject: SO_LINGER dead: I get an immediate RST on 2.6.24?

Hi everybody,

I have an application where I need to send data from A to B, and beforehand,
I don't know how much data this will be. 

B is 'stupid', and consists solely of a TCP/IP port accepting data, and I
have no way to chunk this data. So what I do is issue blocking calls to
write(), shutdown(fd, SHUT_WR), and wait for the fd to become readable which
tells me that the remote has packed up, and I'm good to go.

Before this, I've tried SO_LINGER with various timeouts but nothing helped.

When I tcpdump, I find that my close() is immediately turned into an RST
packet.

Is SO_LINGER a NOOP? Does it still do anything?

I'm about to blog this up - the 'shutdown() and read()' technique is
something I had to purloin from the Apache source.

So I'd love to know the words of the wise on this one.

Thanks.

-- 
http://www.PowerDNS.com      Open source, database driven DNS Software 
http://netherlabs.nl              Open and Closed source services
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