/// <summary>
/// Unregister from Epmd.
/// Other nodes wishing to connect will no longer be able to
/// </summary>
public static void UnPublishPort(ErlLocalNode node)
{
IErlTransport s = null;
try
{
s = node.Epmd ?? new ErlTcpTransport(ErlLocalNode.LocalHost, EPMD_PORT)
{
NodeName = node.NodeName.Value
};
ErlOutputStream obuf = new ErlOutputStream(
writeVersion: false, capacity: node.AliveName.Length + 8);
obuf.Write2BE(node.AliveName.Length + 1);
obuf.Write1((byte)Indicator.StopReq);
var buf = Encoding.ASCII.GetBytes(node.AliveName);
obuf.Write(buf);
obuf.WriteTo(s.GetStream());
node.OnTrace(ErlTraceLevel.Epmd, Direction.Outbound, () =>
StringConsts.ERL_EPMD_UNPUBLISH.Args(node.NodeName.Value, node.Port));
}
catch
{
s = null;
}
finally
{
if (s != null)
{
try { s.Close(); } catch { }
}
node.Epmd = null;
}
}
private void closeSock(IErlTransport s)
{
try { if (s != null)
{
s.Close();
}
}
catch { }
}
/// <summary>
/// Close the connection to the remote node
/// </summary>
protected virtual void Close()
{
m_Connected = false;
if (m_Transport != null)
{
lock (m_Transport)
{
if (m_Transport != null)
{
m_Home.OnTrace(ErlTraceLevel.Ctrl, Direction.Inbound, "CLOSE");
try { m_Transport.Close(); }
catch { }
finally { m_Transport = null; }
}
}
}
}
/// <summary>
/// Determine what port a node listens for incoming connections on
/// </summary>
/// <param name="home">Local node</param>
/// <param name="node">Remote lode for which to look up the port number from remote EPMD</param>
/// <param name="closeSocket">If true, close the connection to remote EPMD at return</param>
/// <returns>the listen port for the specified node, or 0 if the node
/// was not registered with Epmd</returns>
public static int LookupPort(ErlLocalNode home, ErlRemoteNode node,
bool closeSocket = false)
{
IErlTransport s = null;
try
{
var obuf = new ErlOutputStream(writeVersion: false, capacity: 4 + 3 + node.AliveName.Length + 1);
s = node.Epmd;
if (s == null)
{
//create transport
s = ErlTransportFactory.Create(node.TransportClassName, node.NodeName.Value);
s.Trace += (o, t, d, msg) => home.OnTrace(t, d, msg);
//append SSH params to transport
node.AppendSSHParamsToTransport(s);
//connect (I am not sure)
s.Connect(node.Host, EPMD_PORT);
}
// build and send epmd request
// length[2], tag[1], alivename[n] (length = n+1)
obuf.Write2BE(node.AliveName.Length + 1);
obuf.Write1((byte)Indicator.Port4req);
//UPGRADE_NOTE: This code will be optimized in the future;
byte[] buf = Encoding.ASCII.GetBytes(node.AliveName);
obuf.Write(buf);
// send request
obuf.WriteTo(s.GetStream());
home.OnTrace(ErlTraceLevel.Epmd, Direction.Outbound,
StringConsts.ERL_EPMD_LOOKUP_R4.Args(node.NodeName.Value));
// receive and decode reply
// resptag[1], result[1], port[2], ntype[1], proto[1],
// disthigh[2], distlow[2], nlen[2], alivename[n],
// elen[2], edata[m]
buf = new byte[100];
int n = s.GetStream().Read(buf, 0, buf.Length);
if (n < 0)
{
throw new ErlException(StringConsts.ERL_EPMD_NOT_RESPONDING.Args(node.Host, node.AliveName));
}
var ibuf = new ErlInputStream(buf, 0, n, checkVersion: false);
if (Indicator.Port4resp == (Indicator)ibuf.Read1())
{
if (0 == ibuf.Read1())
{
node.Port = ibuf.Read2BE();
node.Ntype = (ErlAbstractNode.NodeType)ibuf.Read1();
node.Proto = ibuf.Read1();
node.DistHigh = ibuf.Read2BE();
node.DistLow = ibuf.Read2BE();
// ignore rest of fields
}
}
if (!closeSocket)
{
node.Epmd = s;
s = null;
}
}
catch (Exception)
{
home.OnTrace(ErlTraceLevel.Epmd, Direction.Inbound, StringConsts.ERL_EPMD_INVALID_RESPONSE_ERROR);
throw new ErlException(StringConsts.ERL_EPMD_NOT_RESPONDING.Args(node.Host, node.AliveName));
}
finally
{
if (s != null)
{
try { s.Close(); } catch { }
}
s = null;
}
home.OnTrace(ErlTraceLevel.Epmd, Direction.Inbound, () =>
node.Port == 0 ? StringConsts.ERL_EPMD_NOT_FOUND : StringConsts.ERL_EPMD_PORT.Args(node.Port));
return(node.Port);
}
/// <summary>
/// Publish node's port at local EPMD, so that other nodes can connect to it.
///
/// On failure to connect to EPMD the function may throw if the value of
/// ErlApp.IgnoreLocalEpmdConnectErrors variable is true.
///
/// On failed connection attempt the function calls
/// node.OnEpmdFailedConnectAttempt delegate
/// </summary>
/// <remarks>
/// This function will get an exception if it tries to talk to an r3
/// epmd, or if something else happens that it cannot forsee. In both
/// cases we return an exception (and the caller should try again, using
/// the r3 protocol).
///
/// If we manage to successfully communicate with an r4 epmd, we return
/// either the socket, or null, depending on the result
/// </remarks>
public static bool PublishPort(ErlLocalNode node)
{
Exception error = null;
IErlTransport s = null;
try
{
ErlOutputStream obuf = new ErlOutputStream(writeVersion: false, capacity: node.AliveName.Length + 20);
s = node.Epmd ?? new ErlTcpTransport(ErlLocalNode.LocalHost, EPMD_PORT)
{
NodeName = node.NodeName.Value
};
obuf.Write2BE(node.AliveName.Length + 13);
obuf.Write1((byte)Indicator.Publish4req);
obuf.Write2BE(node.Port);
obuf.Write1((byte)node.Ntype);
obuf.Write1((byte)node.Proto);
obuf.Write2BE(node.DistHigh);
obuf.Write2BE(node.DistLow);
obuf.Write2BE(node.AliveName.Length);
var buf = Encoding.ASCII.GetBytes(node.AliveName);
//UPGRADE_NOTE: This code will be optimized in the future;
obuf.Write(buf);
obuf.Write2BE(0); // No extra
// send request
obuf.WriteTo(s.GetStream());
node.OnTrace(ErlTraceLevel.Epmd, Direction.Outbound, () =>
StringConsts.ERL_EPMD_PUBLISH.Args(node.AliveName, node.Port, "r4"));
// get reply
buf = new byte[100];
int n = s.GetStream().Read(buf, 0, buf.Length);
if (n < 0)
{
// this was an r3 node => not a failure (yet)
throw new ErlException(StringConsts.ERL_EPMD_NOT_RESPONDING.Args(node.Host, node.AliveName));
}
ErlInputStream ibuf = new ErlInputStream(buf, 0, n, checkVersion: false);
if (Indicator.Publish4resp == (Indicator)ibuf.Read1())
{
int result = ibuf.Read1();
if (result == 0)
{
node.Creation = (byte)ibuf.Read2BE();
node.OnTrace(ErlTraceLevel.Epmd, Direction.Inbound, StringConsts.ERL_EPMD_OK);
node.Epmd = s;
return(true); // success
}
}
error = new ErlException("Cannot register node '{0}' (not unique?)".Args(node.AliveName));
}
catch (Exception e)
{
error = e;
}
// epmd closed the connection = fail
if (s != null)
{
try { s.Close(); } catch { }
}
node.Epmd = null;
node.OnTrace(ErlTraceLevel.Epmd, Direction.Inbound, StringConsts.ERL_EPMD_NO_RESPONSE);
node.OnEpmdFailedConnectAttempt(node.NodeName, error.Message);
node.OnTrace(ErlTraceLevel.Epmd, Direction.Inbound, StringConsts.ERL_EPMD_FAILED_TO_CONNECT_ERROR);
if (!ErlApp.IgnoreLocalEpmdConnectErrors)
{
throw new ErlException(StringConsts.ERL_EPMD_FAILED_TO_CONNECT_ERROR + ": " + error.Message);
}
node.Creation = 0;
return(false);
}
private void closeSock(IErlTransport s)
{
try { if (s != null) s.Close(); }
catch { }
}
