passive close

Hi,
I have a server process that needs to reuse a TCP socket. So I would like
it to always do a passive close. To do this I do the following

char c;
int tmp;
tmp = read(TCPsocket, &c, 1, 0);
while(tmp >= 0 || (errno != ENOTCONN))
{
tmp = read(TCPsocket, &c, 1, 0);
}

The TCPsocket is non-blocking so I check whether read() returns -1 for
some other reason like EWOULDBLOCK.
This loop never ends. So my question is whether read() returns 0 or -1
(with ENOTCONN set) when the remote end sends a FIN pkt. What is the usual
method for ensuring that a server only does a passvive close?

Thank you,
Anant.

In article <Pine.GSO.4.58.0504221210280.14072@mamba.cs.Virginia.EDU>,
Anant Padmanath Mudambi <apm9v@mamba.cs.Virginia.EDU> wrote:

> Hi,
> I have a server process that needs to reuse a TCP socket. So I would like
> it to always do a passive close. To do this I do the following
>
> char c;
> int tmp;
> tmp = read(TCPsocket, &c, 1, 0);
> while(tmp >= 0 || (errno != ENOTCONN))
> {
> tmp = read(TCPsocket, &c, 1, 0);
> }
>
> The TCPsocket is non-blocking so I check whether read() returns -1 for
> some other reason like EWOULDBLOCK.
> This loop never ends. So my question is whether read() returns 0 or -1
> (with ENOTCONN set) when the remote end sends a FIN pkt. What is the usual
> method for ensuring that a server only does a passvive close?

If the remote end sends a FIN segment, read() will return 0 when you've
finished reading everything.  So change 'tmp >= 0' to 'tmp > 0'.

--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***