Hello Sven,

thanks for your fast reply.

On Mon, May 18, 2015 at 11:41 AM, Sven Van Caekenberghe <sven@stfx.eu> wrote:

Hi Manfred,

Did you see/study the example/test UDPSocketEchoTest ?

unfortunately I did not see this class, yet.

But I did look at the Socket class itself and Socket>>timeTestUDP (in Pharo3).

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Also, UDP is very primitive: it is send and forget, returns no errors, and is totally asynchronous. Listening should best be done in a separate process.

Yes, UDP is primitive but the SSDP specification requires using UDP.

Here is how I would write your send part:

��| message udpSocket |
�� message := String crlf join: #(
�� 'M-SEARCH * HTTP/1.1'
�� 'HOST:239.255.255.250:1900'
�� 'MAN:"ssdp:discover'
�� 'ST:ssdp:all'
�� 'MX:1'
�� '').

�� udpSocket := Socket newUDP.
�� udpSocket sendData: message toHost: #[239 255 255 250] port: 1900.
�� udpSocket waitForSendDoneFor: 5.
�� udpSocket closeAndDestroy.

Thanks for this snippet.

For some reasons I do not understand yet, this gives me the expected result in contrast to my own version.

I modified it like this to print the results on the Transcript:

| message udpSocket |

�� message := String crlf join: #(

�� 'M-SEARCH * HTTP/1.1'

�� 'HOST:239.255.255.250:1900'

�� 'MAN:"ssdp:discover"'

�� 'ST:ssdp:all'

�� 'MX:1'

�� '').

�� udpSocket := Socket newUDP.

�� udpSocket sendData: message toHost: #[239 255 255 250] port: 1900.

�� udpSocket waitForSendDoneFor: 5.

�� udpSocket waitForData.

�� [udpSocket dataAvailable ] whileTrue: [ | buffer |

�� buffer := ByteArray new: 1024.

�� udpSocket receiveUDPDataInto: buffer.

�� Transcript show: 'Received: ', buffer.

�� [udpSocket waitForDataFor: 1] on: Error do: [ ��].

�� ].

�� udpSocket closeAndDestroy.

Currently, this will work for me, since I am not interested in continuously detecting new devices.

But you mentioned reading should in general be done in a separate process.

Would you reuse the existing udpSocket instance in this case or create a separate one for reading?

Maybe nothing came back because the line ends where wrong ?

The lineendings I used are required by the SSDP specification.

��

HTH,

Sven

Thanks,

Manfred

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> On 18 May 2015, at 11:29, Manfred Kr��hnert <mkroehnert42@googlemail.com> wrote:
>
> Hello everyone,
>
> I am currently trying to get a list of UPnP device via SSDP (Simple Service Discovery Protocol).
>
> A minimalistic working NodeJS example looks like this:
>
>�� var dgram = require('dgram');
>�� var message = new Buffer(
>�� "M-SEARCH * HTTP/1.1\r\n" +
>�� "HOST:239.255.255.250:1900\r\n" +
>�� "MAN:\"ssdp:discover\"\r\n" +
>�� "ST:ssdp:all\r\n" +
>�� "MX:1\r\n" +
>�� "\r\n"
>�� );
>
>�� var client = dgram.createSocket("udp4");
>
>�� client.on("message", function (msg, rinfo) {
>�� console.log("server got: " + msg + " from " + rinfo.address + ":" + rinfo.port);
>�� });
>�� client.send(message, 0, message.length, 1900, "239.255.255.250");
>�� client.close();
>
> I tried to recreate the same functionality in Pharo with the following piece of code:
>
>�� | message udpSocket host |
>�� message := 'M-SEARCH * HTTP/1.1\r\n' ,
>�� 'HOST:239.255.255.250:1900\r\n' ,
>�� 'MAN:"ssdp:discover"\r\n' ,
>�� 'ST:ssdp:all\r\n' ,
>�� 'MX:1\r\n' , '\r\n'.
>
>�� udpSocket := Socket newUDP.
>�� host :=�� (NetNameResolver addressFromString: '239.255.255.250').
>�� udpSocket sendData: message toHost: host port: 1900.
>�� "udpSocket waitForData."
>�� Transcript show: 'Received: ' , udpSocket receiveData.
>�� udpSocket closeAndDestroy.
>
> Unfortunately, this script hangs both in Pharo3 and Pharo4 (OS X 10.10, Pharo 30856 and 40611).
> When I interrupt with Cmd+. the debugger shows the method
>�� Socket>>waitForDataIfClosed:
> and the hang is apparently in the line
>�� self readSemaphore wait
>
> Could anyone give me some advice if I should to do this differently or what the issue with the Pharo script is?
>
> Thanks in advance,
> Manfred