I am developing an application for opendaylight Carbon where I need to know the MAC address of the switch. Can I determine this from the DpnId when the switch connects? Thanks.
Not sure which MAC you are referring to. If you are referring MAC address of each ofport of the DPN then you can register listener for FlowCapableNodeConnector model and you can get MAC by calling FlowCapableNodeConnector#getHardwareAddress in add method of listener. And if you are talking about VM/packet Source/destination MAC, then you first you need to punt the packet to controller and then you can use PacketProcessingListener and extract MAC as shown below.
public void onPacketReceived(PacketReceived notification) {
final short tableId = notification.getTableId().getValue();
final byte[] data = notification.getPayload();
Ethernet res = new Ethernet();
try {
res.deserialize(data, 0, data.length * NetUtils.NumBitsInAByte);
} catch (Exception e) {
LOG.warn("PacketInHandler: Failed to decode Packet ", e);
return;
}
try {
Packet pkt = res.getPayload();
LOG.info("Packet type is ->{}", pkt.getClass().getName());
if (pkt instanceof IPv4) {
IPv4 ipv4 = (IPv4) pkt;
byte[] srcMac = res.getSourceMACAddress();
byte[] dstMac = res.getDestinationMACAddress();
}
}
}
The DPID uniquely identifies the switch. The MAC address is generally not exposed.
Moreover, the switch itself generally does not have a MAC address
(they may have tens of MAC addresses for different functions/interfaces).
Switches work at a lower level, though, they work with MAC addresses.
Related
I'm kind of new to Android I'm working
mostly on i2s adafruit microphone
also on typical USB microphone
with Android things on Raspberry pi.
Android documentation says it supports USB mic since Preview 2, but I couldn't find any example.
https://developer.android.com/things/preview/releases.html
So I'm on i2s microphone for now and stuck here.
Code
// I2S Device Name
private static final String I2S_DEVICE_NAME = "I2S1";
private static final AudioFormat AUDIO_FORMAT_STEREO =
new AudioFormat.Builder()
.setChannelMask(AudioFormat.CHANNEL_IN_STEREO)
.setEncoding(AudioFormat.ENCODING_PCM_16BIT)
.setSampleRate(44100)
.build();
private I2sDevice mDevice;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String str = "";
// Attempt to access the I2C device
try {
PeripheralManagerService manager = new PeripheralManagerService();
mDevice = manager.openI2sDevice(I2S_DEVICE_NAME, AUDIO_FORMAT_STEREO, I2sDevice.PCM_FORMAT_16_BIT);
} catch (IOException e) {
Log.w(TAG, "Unable to access I2S device", e);
}
// Set up the audio playback sink
int bufferSize = AudioTrack.getMinBufferSize(
AUDIO_FORMAT_STEREO.getSampleRate(),
AUDIO_FORMAT_STEREO.getChannelMask(),
AUDIO_FORMAT_STEREO.getEncoding());
str += String.valueOf(bufferSize) + " ";
// Transfer data from input to output
ByteBuffer buffer = ByteBuffer.allocate(bufferSize);
try{
int read = mDevice.read(buffer, bufferSize);
str += String.valueOf(read);
} catch (IOException e) {
Log.w(TAG, "Unable to access I2S1 device", e);
}
TextView myText = (TextView) findViewById(R.id.mytextview);
myText.setText(str);
}
Problem
At line:
mDevice.read()
android monitor says
I2S1 error: Cannot read from output-only device (Operation not
permitted) (code 1)
Can I get any help?
Android documentation says it supports USB mic since Preview 2, but I couldn't find any example.
A USB microphone is automatically detected and set up as the default mic input on the device. You can reference any standard Android audio recording sample that sets the audio source to MIC. As one example, here is the API Guide for MediaRecorder.
I2S1 error: Cannot read from output-only device (Operation not permitted) (code 1)
What version of the Android Things support library are you using in your code? If you aren't on the latest (0.5.1 for both the OS image and the library) I would recommend updating first. You might also try changing your code to use the version of openI2sDevice() that accepts direction flags. The version you are using has been deprecated in the latest releases.
Has anyone heard of any issues with MessageDialog's not displaying on Windows 8 tablets? Or more specifically Samsung 700t? It uses a regular intel process and not ARM. I built the app on a laptop and the messagedialog shows when debugging from the laptop, shows on the tablet simulator but doesn't show on the actual tablet.
I'm using the Caliburn.Micro IResult interface to display the messagedialog in the view.
Heres snippits of code that I'm using:
public IEnumerable<IResult> NavExecute(String method)
{
Windows.UI.ViewManagement.ApplicationView.TryUnsnap();
var conn = NetworkInformation.GetInternetConnectionProfile();
if (conn.GetNetworkConnectivityLevel() != NetworkConnectivityLevel.InternetAccess)
{
yield return new MessageDialogResult("Internet Connection Not Detected", "Connection Error");
netOn = false;
}
}
the above is in my view model base class, and heres the implementation of the IResult class itself:
public class MessageDialogResult : ResultBase
{
private readonly string _content;
private readonly string _title;
public MessageDialogResult(string content, string title)
{
_content = content;
_title = title;
}
public async override void Execute(ActionExecutionContext context)
{
var dialog = new MessageDialog(_content, _title);
await dialog.ShowAsync();
OnCompleted();
}
}
I doub't it's an issue with the code since I'm debugging in x86 mode on both devices (before anyone asks why I'm not debugging for all devices it's because I'm using SQLite which requires a seperate package for each arhitecture.)
I'm not sure if theres a setting somewhere in Windows 8 that disables in app popups, but I couldn't find one.
Any ideas?
Are you handling the callback of Coroutine.Execute?
The callback on Execute might be calling back with an exception thrown by the coroutine - this would silently fail if you weren't explicitly looking for it in the callback
Coroutine.Execute(YourEnumerator(), new ActionExecutionContext { Blah }, (o, e) => {
if(e.Error != null) // Something went wrong
});
Maybe the async await is throwing or something like that (can't think why!)
Edit:
Ah additionally stuff in your enumerator could also throw:
Windows.UI.ViewManagement.ApplicationView.TryUnsnap();
var conn = NetworkInformation.GetInternetConnectionProfile();
Either one could throw making the outer enumerator swallow an exception if not handled in the callback - or could be a nullref on conn?
The reason why GetInternetConnectionProfile() was returning a null ref was due to the fact that when on a laptop, if you disconnect from a wireless connection the laptop's internet connection profile defaults to ethernet, whereas the tablet (at least the Samsung 700T) doesn't have an ethernet port so it's connection profile doesn't exist if a wireless connection isn't established.
Thanks to Charleh for pointing me in the right direction.
i am new to this forum and the whole thing with Processing.
I have a specific question to ask and thanks a lot for your time and thoughts!
How can i connect my Arduino with Ethernet Shield, getting temperature values from a sensor so they can be seen to a processing script?
In a straight Arduino script, one gets the value, connects from the ethernet shield to a server and does what one likes. I have accomplished that.
In my case i want Arduino to just run the script of reading an analog input value from the sensor.
Is it possible?
I have made the serial connection work and read the values alright through the usb, but with ethernet shield? How can i get the value that arduino reads WITHOUT USB/Serial connection?
ps. i am using WAMP server etc, Windows 7
I am trying the UDP connection script example for both arduino and processing from http://arduino.cc/en/Tutorial/UDPSendReceiveString, but
1)i ain't sure if that's what i need,
2)i have excluded from firewall ports 6000, 8888 for my tests and have put the IP address of my Arduino at the Arduino script and "localhost" at the Processing script
THE CODE COPIED FOR BETTER USE HERE
/*
UDPSendReceive.pde:
This sketch receives UDP message strings, prints them to the serial port
and sends an "acknowledge" string back to the sender
A Processing sketch is included at the end of file that can be used to send
and received messages for testing with a computer.
created 21 Aug 2010
by Michael Margolis
This code is in the public domain.
*/
#include <SPI.h> // needed for Arduino versions later than 0018
#include <Ethernet.h>
#include <EthernetUdp.h> // UDP library from: bjoern#cs.stanford.edu 12/30/2008
// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 1, 177);
unsigned int localPort = 8888; // local port to listen on
// buffers for receiving and sending data
char packetBuffer[UDP_TX_PACKET_MAX_SIZE]; //buffer to hold incoming packet,
char ReplyBuffer[] = "acknowledged"; // a string to send back
// An EthernetUDP instance to let us send and receive packets over UDP
EthernetUDP Udp;
void setup() {
// start the Ethernet and UDP:
Ethernet.begin(mac,ip);
Udp.begin(localPort);
Serial.begin(9600);
}
void loop() {
// if there's data available, read a packet
int packetSize = Udp.parsePacket();
if(packetSize)
{
Serial.print("Received packet of size ");
Serial.println(packetSize);
Serial.print("From ");
IPAddress remote = Udp.remoteIP();
for (int i =0; i < 4; i++)
{
Serial.print(remote[i], DEC);
if (i < 3)
{
Serial.print(".");
}
}
Serial.print(", port ");
Serial.println(Udp.remotePort());
// read the packet into packetBufffer
Udp.read(packetBuffer,UDP_TX_PACKET_MAX_SIZE);
Serial.println("Contents:");
Serial.println(packetBuffer);
// send a reply, to the IP address and port that sent us the packet we received
Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
Udp.write(ReplyBuffer);
Udp.endPacket();
}
delay(10);
}
/*
Processing sketch to run with this example
=====================================================
// Processing UDP example to send and receive string data from Arduino
// press any key to send the "Hello Arduino" message
*/
import hypermedia.net.*;
UDP udp; // define the UDP object
void setup() {
udp = new UDP( this, 6000 ); // create a new datagram connection on port 6000
//udp.log( true ); // <-- printout the connection activity
udp.listen( true ); // and wait for incoming message
}
void draw()
{
}
void keyPressed() {
String ip = "192.168.1.177"; // the remote IP address
int port = 8888; // the destination port
udp.send("Hello World", ip, port ); // the message to send
}
void receive( byte[] data ) { // <-- default handler
//void receive( byte[] data, String ip, int port ) { // <-- extended handler
for(int i=0; i < data.length; i++)
print(char(data[i]));
println();
}
Read those values into a file and use that file to send data to processing. http://py.processing.org/reference/createReader.html
Great scheme. Only one problem. It works perfectly on my system. I loaded my Arudino Uno R3 with your Arduino sketch and loaded the Processing sketch as well. Worked like a charm, first try. Didn't change anything on my Arduino, Windows system, Processing (2.0.3), network, etc.
Could be you have a Arduino board problem (unlikely) or an Ethernet shield problem (sadly, more likely). You could have a network problem (even more likely).
Try Wireshark. You will really just be guessing until you take a look at the Wireshark output. Note that Wireshark has filters. You will need them. Filter out all of the non-UDP traffic.
At the moment I have an Arduino board with an Ethernet Shield connected to a router. My computer connects to this router via Wi-Fi. My board and my computer send UDP messages back and forth to each other. My computer is a client, and the board is a server. However I noticed, that when I send a longer UDP message from my computer, and then a shorter UDP message, the Arduino accepts the shorter message, then followed by remaining bits from the longer message.
For instance: if I send "Hello World" from my computer, followed with "Test"; the Arduino will not read the second message as "Test", but rather: "Testo World".
I thought perhaps in was a problem from the Arduino end first. The Arduino stores the messages temporarily in an array called packetBuffer. I tried clearing this buffer before I receive a new message each time. The buffer would clear, but then I would receive the faulty message again.
So I assume the culprit is the computer, the client. On the computer end I have a processing sketch that sends the UDP messages. The example below is not the sketch itself; however it is by far a simpler example that still provides the exact symptoms as I described with my original sketch.
import hypermedia.net.*;
UDP udp; // define the UDP object
void setup() {
udp = new UDP( this, 6000 ); // Create a new datagram connection on port 6000
//udp.log( true ); // <-- printout the connection activity
udp.listen( true ); // and wait for incoming message
}
void keyPressed() {
String IPaddress = "192.168.1.177"; // The remote IP address
int port = 8888; // The destination port
if (keyCode == UP)
{
udp.send("Test", IPaddress, port );
}
else
if (keyCode == DOWN)
{
udp.send("Hello World", IPaddress, port );
}
}
void receive( byte[] data ) { // <-- default handler
//void receive( byte[] data, String IPaddress, int port ) { // <-- extended handler
for(int i=0; i < data.length; i++)
print(char(data[i]));
println();
}
How could I get the sketch to send the right messages?
Of course I am more than willing to provide more information.
There wasn't a direct solution to this problem; so I ended up resorting to a work around. The work around involves dynamically adding zeros to all strings sent to the Arduino so there is always 10 characters sent.
For instance:
If I am to send "Hello Bot", the actual string sent is "Hello Bot0". If I sent an additional message like "Test" after that, the string sent to the Arduino would be "Test000000". The additional zeros would cover up the overlapping characters. One problem with this work around is that I had to prepare the Arduino to accept the zeros also. This work around is also kind of messy for the code. It does work though.
Here's a snippet of code from the computer (client) side. The Arduino code obviously just had to be adjusted to account for the zeros.
public void Send() { //bang button named "Send" activates function
String txtSend = comField.getText(); //Grab text from a textbox to be sent
int txtSendLength = txtSend.length();
for(int i = 0; i < 10-txtSendLength; i++){ //Add zeros until it has 10 char
txtSend = txtSend + "0";
}
udp.send(txtSend, ip, port);
comField.clear(); //Clear the textbox
}
Behold, the very simple and crude solution!
I believe your issue is with properly clearing the buffer. I found a line of code that goes through and clears each character, since it is a character array. There is theoretically no buffer to clear once it is read.
Use:
for(int i=0;i<UDP_TX_PACKET_MAX_SIZE;i++) packetBuffer[i] = 0;
Once you read the data, and that will clear the array. I also found out that when trying to do logic on the data that was received, in order to control some output, I needed to first convert the packetBuffer to a string. After that, all seemed to work correctly.
Hope that help.
I'm writing some JVM instance related application and looking at open source to see how it's solve some problems. The JConsole from JDK7 collects running VMs in two ways (look at source licensed by GPL2 in jdk/src/share/classes/sun/tools/jconsole/LocalVirtualMachine.java). The first is jvmstat way, code like this:
private static void getMonitoredVMs(Map<Integer, LocalVirtualMachine> map) {
MonitoredHost host;
Set vms;
try {
host = MonitoredHost.getMonitoredHost(new HostIdentifier((String)null));
vms = host.activeVms();
} catch (java.net.URISyntaxException sx) {
throw new InternalError(sx.getMessage());
} catch (MonitorException mx) {
throw new InternalError(mx.getMessage());
}
for (Object vmid: vms) {
if (vmid instanceof Integer) {
int pid = ((Integer) vmid).intValue();
String name = vmid.toString(); // default to pid if name not available
boolean attachable = false;
String address = null;
try {
MonitoredVm mvm = host.getMonitoredVm(new VmIdentifier(name));
// use the command line as the display name
name = MonitoredVmUtil.commandLine(mvm);
attachable = MonitoredVmUtil.isAttachable(mvm);
address = ConnectorAddressLink.importFrom(pid);
mvm.detach();
} catch (Exception x) {
// ignore
}
map.put((Integer) vmid,
new LocalVirtualMachine(pid, name, attachable, address));
}
}
}
Second is attach way, and looks like this:
private static void getAttachableVMs(Map<Integer, LocalVirtualMachine> map) {
List<VirtualMachineDescriptor> vms = VirtualMachine.list();
for (VirtualMachineDescriptor vmd : vms) {
try {
Integer vmid = Integer.valueOf(vmd.id());
if (!map.containsKey(vmid)) {
boolean attachable = false;
String address = null;
try {
VirtualMachine vm = VirtualMachine.attach(vmd);
attachable = true;
Properties agentProps = vm.getAgentProperties();
address = (String) agentProps.get(LOCAL_CONNECTOR_ADDRESS_PROP);
vm.detach();
} catch (AttachNotSupportedException x) {
// not attachable
} catch (IOException x) {
// ignore
}
map.put(vmid, new LocalVirtualMachine(vmid.intValue(),
vmd.displayName(),
attachable,
address));
}
} catch (NumberFormatException e) {
// do not support vmid different than pid
}
}
}
My question: why it uses two different tools for retrieving virtual machines list? I know that through attach api you can list VMs running by this same JRE only, but jvmstat can give you list of all VMs running with any JRE versions. I have tested JRE/JDK 7 32 and 64-bit only because theys and newer are my target, sadly on windows only. Is not suffiecient to use jvmstat only? Is there any case when some VM is visible by attach api, but jvmstat can't see it?
Usually, for finding all jvm process, attach api is equal to jvmstat. But in some customized circumstances, it's diffrent. And the diffrent is com.sun.tools.attach.spi.AttachProvider.
e.g. in Windows platform, jvmstat finds java process by listing all files in the directory %TEMP%/hsperfdata_caoxudong(In linux, it is /tmp/hsperfdata_caoxudong). And attach api finds java processes by AttachProvider instance. jdk provides a default an AttachProvider implementation, which depends on your OS platform. In Windows Platform, the implementation is sun.tools.attach.WindowsAttachProvider. In its listVirtualMachines method, if isTempPathSecure method return false, it will iterate all processes, and find all processes, which loaded library "jvm.dll". You can install your own AttachProvider implementation to find java processes with your own ways, and the result may be diffrent with jvmstat.
The installation of AttachProvider is here.