Re: [BEHAVE] (no subject)

[ivan c <[e-mail]>]

On Thu, 27 Jun 2013 14:23:48 +0200, Simon Perreault
<[e-mail]> wrote:
> 
> connect()ing UDP sockets has two big advantages:
> 
> 1) It allows using the same programming model for UDP and TCP. More code

> can be factored out, which is good software engineering.

Usually applications use UDP and TCP differently and for different things,
but that's an interesting point.


> 2) It propagates ICMP errors up through the BSD API, allowing 
> straightforward error handling that is again similar to TCP and can be 
> factored out. For non-connected UDP sockets, ICMP errors are simply
> ignored.

All errors (including ICMP) are received for all UDP sockets.
If you call select() on your sockets, the sockets with the errors will be
select()-ed, and the subsequent recvfrom() call will return the error code.
An ICMP message will trigger a ECONNRESET error I think.


> Since file descriptors are basically free, come at no additional 
> performance cost when you use something like epoll, kqueue, or windows 
> IOCP, and since this method does not consume additional ports, I 
> recommend it over sendto()/recvfrom() when I teach network programming.
> 
> This comes from W. Richard Stevens "UNIX Network Programming". The 
> technique is used a lot in the wild. I'm not inventing anything.


-- 
_Ivan Chollet_