setsockopt in child_main

[Igor Tatarinov <ta...@prairie.NoDak.edu>]

Correct me if I am wrong but currently socket options (KEEPALIVE and
SND_BUF, SO_LINGER) are only set for the listening sockets (in make_sock). 

If all these options were inherited on accept, everything would be fine but
TCP_NODELAY seems to be an exception (disable_ nagle is also called in
child_main). So it is not inherited? (I checked it isn't; throughput
degarades significantly without it). 

I suspect all others are not inherited either so they have to be set again
(actually the listening sockets do not probably require a large buffer). I
may be wrong though.

any ideas?

thanks,
igor

Re: setsockopt in child_main

[Marc Slemko <ma...@worldgate.com>]

On Mon, 5 Jan 1998, Marc Slemko wrote:

> SO_DEBUG, SO_DONTROUTE, SO_KEEPALIVE, SO_LINGER, SO_OOBINLINE, SO_RCVBUF
> and SO_SNDBUF are inherited; if not, your system is broken.

Oh, cf. R. Stevens "Unix Network Programming", volume one, second edition,
page... erm.... 183 for details.

> 
> Some of them have to be, since after the connection is established it can
> be too late to set them; eg. buffer sizes are related to the window scale
> option which is negotiated before accept() returns. 
> 
> On Mon, 5 Jan 1998, Igor Tatarinov wrote:
> 
> > Correct me if I am wrong but currently socket options (KEEPALIVE and
> > SND_BUF, SO_LINGER) are only set for the listening sockets (in make_sock). 
> > 
> > If all these options were inherited on accept, everything would be fine but
> > TCP_NODELAY seems to be an exception (disable_ nagle is also called in
> > child_main). So it is not inherited? (I checked it isn't; throughput
> > degarades significantly without it). 
> > 
> > I suspect all others are not inherited either so they have to be set again
> > (actually the listening sockets do not probably require a large buffer). I
> > may be wrong though.
> > 
> > any ideas?
> > 
> > thanks,
> > igor
> > 
> 

Re: setsockopt in child_main

[Marc Slemko <ma...@worldgate.com>]

SO_DEBUG, SO_DONTROUTE, SO_KEEPALIVE, SO_LINGER, SO_OOBINLINE, SO_RCVBUF
and SO_SNDBUF are inherited; if not, your system is broken.

Some of them have to be, since after the connection is established it can
be too late to set them; eg. buffer sizes are related to the window scale
option which is negotiated before accept() returns. 

On Mon, 5 Jan 1998, Igor Tatarinov wrote:

> Correct me if I am wrong but currently socket options (KEEPALIVE and
> SND_BUF, SO_LINGER) are only set for the listening sockets (in make_sock). 
> 
> If all these options were inherited on accept, everything would be fine but
> TCP_NODELAY seems to be an exception (disable_ nagle is also called in
> child_main). So it is not inherited? (I checked it isn't; throughput
> degarades significantly without it). 
> 
> I suspect all others are not inherited either so they have to be set again
> (actually the listening sockets do not probably require a large buffer). I
> may be wrong though.
> 
> any ideas?
> 
> thanks,
> igor
>