Re: udp support

[Alex Shinn <alexshinn@xxxxxxxxx>]

On Mon, Sep 1, 2014 at 1:40 PM, John Cowan <cowan@xxxxxxxxxxxxxxxx> wrote:

Alex Shinn scripsit:

> I'm in the process of porting hato to R7RS and was
> considering using SRFI 106.

I haven't checked lately, but ISTR that SRFI 106 was only meant for TCP.

It describes itself as a general socket API and provides *sock-dgram*.

If it were meant only for TCP a much simpler design would seem to

be called for.

Although looking again it seems there's no way to get the remote

client ip for sockets returned by `socket-accept'?  You can write

TCP servers without this, but it's pretty important for logging and

blacklisting, etc.  On the other hand, you can't write a UDP server

without access to the client address.

> Am I missing something or is there no way to get the
> client host or port when receiving udp packets?
> Chicken and Racket handle this by returning multiple
> values.  Chibi follows C and uses a mutable address
> parameter.

You might want to look at
<http://trac.sacrideo.us/wg/wiki/DatagramChannelsCowan>,
which tracks the C API fairly closely.

Thanks, I'll take a closer look at this later.

How can datagram-channel-receive-from truncate when the

length is longer than requested?  Just about the only thing UDP

guarantees is that you will never even see a truncated packet.

-- 

Alex