private async Task UdpReceiveMessagesAsync(Socket socket, CancellationToken cancellationToken, Func <SyslogMessage, CancellationToken, Task> callback)
{
byte[] buffer = new byte[1024];
int readSize = 0;
try
{
EndPoint sender = new IPEndPoint(IPAddress.Loopback, 0);
while ((readSize = await UdpReceiveBufferAsync(socket, buffer, 0, 1024, sender, SocketFlags.None)) > 0)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
if (readSize > MaxMessageSize)
{
Trace.WriteLine("Maximum message size exceeded. Closing socket.");
return;
}
SyslogMessage sm = null;
if (SyslogMessage.TryParse(((IPEndPoint)sender).Address, Encoding.ASCII.GetString(buffer, 0, readSize), out sm))
{
await callback(sm, cancellationToken);
}
}
}
finally
{
try { if (socket.Connected)
{
socket.Close();
}
} catch (SocketException ex) { Trace.WriteLine($"{ex.Message} ({ex.GetType()})"); }
}
}
static public bool TryParse(IPAddress sender, string message, out SyslogMessage logmsg)
{
logmsg = new SyslogMessage(sender);
Match msgMatch;
if (sender == null || string.IsNullOrEmpty(message))
{
return(false);
}
if (!(msgMatch = _reRFC5234.Match(message)).Success)
{
Trace.WriteLine($"Could not understand received message '{message}'.");
return(false);
}
string strValue;
int intValue;
DateTime dtValue;
if (msgMatch.Groups["PRI"].Success &&
!string.IsNullOrWhiteSpace((strValue = msgMatch.Groups["PRI"].Value)) &&
Int32.TryParse(strValue.Substring(1, strValue.Length - 2), out intValue))
{
logmsg.Facility = (SyslogFacility)Math.Floor((double)intValue / 8);
logmsg.Severity = (SyslogSeverity)(intValue % 8);
}
if (msgMatch.Groups["VER"].Success &&
!string.IsNullOrWhiteSpace((strValue = msgMatch.Groups["VER"].Value)) &&
Int32.TryParse(strValue, out intValue))
{
logmsg.Version = intValue;
}
if (msgMatch.Groups["TS"].Success &&
!string.IsNullOrWhiteSpace((strValue = msgMatch.Groups["TS"].Value)) &&
DateTime.TryParse(strValue, null, System.Globalization.DateTimeStyles.RoundtripKind, out dtValue))
{
logmsg.Timestamp = dtValue;
}
if (msgMatch.Groups["HOST"].Success &&
!string.IsNullOrWhiteSpace((strValue = msgMatch.Groups["HOST"].Value)))
{
logmsg.Hostname = strValue;
}
if (msgMatch.Groups["APP"].Success &&
!string.IsNullOrWhiteSpace((strValue = msgMatch.Groups["APP"].Value)))
{
logmsg.AppName = strValue;
}
if (msgMatch.Groups["PID"].Success &&
!string.IsNullOrWhiteSpace((strValue = msgMatch.Groups["PID"].Value)))
{
logmsg.ProcId = strValue;
}
if (msgMatch.Groups["MSGID"].Success &&
!string.IsNullOrWhiteSpace((strValue = msgMatch.Groups["MSGID"].Value)))
{
logmsg.MsgId = strValue;
}
if (msgMatch.Groups["SD"].Success &&
!string.IsNullOrWhiteSpace((strValue = msgMatch.Groups["SD"].Value)))
{
var sdMatch = _reSD.Match(msgMatch.Groups["SD"].Value.Trim('[', ']', ' '));
foreach (Capture kvTerm in sdMatch.Groups["term"].Captures)
{
Capture sdKey = null;
foreach (Capture keyMatch in sdMatch.Groups["prefix"].Captures)
{
if (keyMatch.Index >= kvTerm.Index && keyMatch.Index <= kvTerm.Index + kvTerm.Length)
{
sdKey = keyMatch;
break;
}
}
if (sdKey == null)
{
if (!logmsg.Data.ContainsKey(kvTerm.Value))
{
logmsg.Data.Add(kvTerm.Value, null);
}
continue;
}
Capture sdValue = null;
foreach (Capture termStringMatch in sdMatch.Groups["termString"].Captures)
{
if (termStringMatch.Index >= kvTerm.Index && termStringMatch.Index <= kvTerm.Index + kvTerm.Length)
{
sdValue = termStringMatch;
break;
}
}
if (!logmsg.Data.ContainsKey(sdKey.Value))
{
logmsg.Data.Add(sdKey.Value, sdValue?.Value.Trim(' ', '"'));
}
}
}
if (msgMatch.Groups["MSG"].Success)
{
logmsg.Content = msgMatch.Groups["MSG"].Value;
}
return(true);
}
static public bool TryParse(IPAddress sender, byte[] message, out SyslogMessage logmsg)
{
return(TryParse(sender, Encoding.ASCII.GetString(message), out logmsg));
}
private async Task TcpReceiveMessageAsync(Socket socket, CancellationToken cancellationToken, Func <SyslogMessage, CancellationToken, Task> callback)
{
byte[] buffer = new byte[1024];
int readSize = 0;
StringBuilder txt = new StringBuilder();
try
{
while (socket.Connected && (readSize = await TcpReceiveBufferAsync(socket, buffer, 0, buffer.Length, SocketFlags.None)) > 0)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
if (txt.Length + readSize > MaxMessageSize)
{
Trace.WriteLine("Maximum message size exceeded. Closing socket.");
return;
}
var s = Encoding.ASCII.GetString(buffer, 0, readSize);
int idx = 0;
if ((idx = s.IndexOf("\n")) > -1)
{
txt.Append(s.Substring(0, idx));
SyslogMessage sm = null;
if (SyslogMessage.TryParse(((IPEndPoint)socket.RemoteEndPoint).Address, txt.ToString(), out sm))
{
await callback(sm, cancellationToken);
}
txt = new StringBuilder(s.Substring(idx + 1));
continue;
}
else
{
txt.Append(s);
}
}
if (txt.Length == 0)
{
return; // Timeout or socket error
}
SyslogMessage msg;
if (SyslogMessage.TryParse(((IPEndPoint)socket.RemoteEndPoint).Address, txt.ToString(), out msg))
{
await callback(msg, cancellationToken);
}
}
finally
{
try { if (socket.Connected)
{
socket.Close();
}
} catch (SocketException) { }
}
}
