this very simple UDP client/server.. doesn't work?

[Jack Klein]

On Mon, 04 Aug 2003 04:37:26 GMT, "Adam M." <adamm@san.rr.com> wrote
in comp.lang.c:

> Hi, I'm trying to get a simple UDP client/server working.

In the future please leave comp.lang.c out of crossposts like this.
The standard C language has no support for sockets or any sort of
networking.

> #include <sys/socket.h>
> #include <netinet/in.h>

The two headers above are not part of the C language and are off-topic
here.

--
Jack Klein
Home: [url]http://JK-Technology.Com[/url]
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[Adam M.]

On Mon, 04 Aug 2003 04:37:26 GMT, Adam M. <adamm@san.rr.com> wrote:

> Hi, I'm trying to get a simple UDP client/server working.
> [snip]

Sorry, I'm an idiot.

It wasn't working due to 'iptables' blocking the packets. I can't believe
I forgot about that.

Wellp, nothing to see here, move along. Just another useless usenet post.
:-)

[Monisha Barooah]

"Adam M." <adamm@san.rr.com> wrote in message news:<oprtc8i7drr2zrv2@news-server.san.rr.com>...

> On Mon, 04 Aug 2003 04:37:26 GMT, Adam M. <adamm@san.rr.com> wrote:
>

> > Hi, I'm trying to get a simple UDP client/server working.
> > [snip]

> Sorry, I'm an idiot.
>
> It wasn't working due to 'iptables' blocking the packets. I can't believe
> I forgot about that.
>
> Wellp, nothing to see here, move along. Just another useless usenet post.
> :-)

Hi Adam,

e = recvfrom(s, buf, sizeof(buf), 0, NULL, NULL);

You are using recvfrom and not even specified the IP address from
which to receive the packet?

I think that is the problem.

Monisha

[Rainer Temme]

"Monisha Barooah" <monishabarooah@yahoo.com> schrieb im Newsbeitrag
news:68ef19de.0308040309.2116a269@posting.google.c om...

> "Adam M." <adamm@san.rr.com> wrote in message

news:<oprtc8i7drr2zrv2@news-server.san.rr.com>...

> > On Mon, 04 Aug 2003 04:37:26 GMT, Adam M. <adamm@san.rr.com> wrote:
> >

> > > Hi, I'm trying to get a simple UDP client/server working.
> > > [snip]

> > Sorry, I'm an idiot.
> >
> > It wasn't working due to 'iptables' blocking the packets. I can't

believe

> > I forgot about that.
> >
> > Wellp, nothing to see here, move along. Just another useless usenet

post.

> > :-)

>
>
> Hi Adam,
>
> e = recvfrom(s, buf, sizeof(buf), 0, NULL, NULL);
>
> You are using recvfrom and not even specified the IP address from
> which to receive the packet?
>
> I think that is the problem.
>
> Monisha

If he only wants to receive packets, then it's ok the specify NULL-pointers.

However, if his server would ever like to answer the params are required,
otherwise he would indeed have no information about the sender.

Anyway, to my knowledge, the from- and fromlen- parameters
in the recvfrom() call are not intended to be used as a filter to
specify a certain address from which you want to receive packets
now. (If you want a datagram-socket to become part of a
one to one association you might want to call connect()
on the serverside (!!) )

regards ... rainer