/// <summary>
/// Flushes all buffers that contain data by calling each buffer handler's StoreMessages method.
/// </summary>
public void Flush()
{
// Get a fast, one-way, read-only enumer of the buffers' keys
var enumer = _buffers.Keys.GetEnumerator();
List <string[]> copiedList = null;
// Ensure that a buffer is defined
if (enumer.Current == null)
{
enumer.MoveNext();
}
while (enumer.Current != null)
{
var currentVal = _buffers[enumer.Current];
// Lock the buffer while a copy is made so that new entries being added do not block or fail the copy.
lock (currentVal)
{
try
{
if (currentVal.Count > 0)
{
copiedList = DeepCopy(currentVal);
// Ensure that the copied object contains the same number of messages.
if (copiedList.Count != currentVal.Count)
{
EventLogger.LogEvent("An error occured while storing messages for " + enumer.Current,
System.Diagnostics.EventLogEntryType.Error);
}
// Clear the buffer.
currentVal.Clear();
}
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not store messages from " + enumer.Current + " because: " + ex.Message,
System.Diagnostics.EventLogEntryType.Error);
}
finally
{
Monitor.Pulse(currentVal);
}
}
if (copiedList != null && copiedList.Count > 0)
{
try
{
// Get a refence to the storer interface of the handler
var storer = _handlers[enumer.Current].GetStorer();
if (storer != null)
{
//Process the list of messages
if (!storer.StoreMessages(copiedList))
{
EventLogger.LogEvent("An error occured while storing messages for " + enumer.Current,
System.Diagnostics.EventLogEntryType.Warning);
}
else
{
copiedList.Clear();
}
}
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not store message from " + enumer.Current + " because: " + ex.Message,
System.Diagnostics.EventLogEntryType.Warning);
}
}
enumer.MoveNext();
}
}
/// <summary>
/// Creates a socket that waits for traffic and sets up the handler modules
/// </summary>
/// <returns>Returns true if the listener starts successfully. Otherwise, false.</returns>
public bool Start()
{
HandlerSection handlers;
// Get the handlers collection
Trace.WriteLine("Loading handlers");
try
{
handlers = (HandlerSection)System.Configuration.ConfigurationManager.GetSection("handlerSection");
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not load configuration because: " + ex.Message, System.Diagnostics.EventLogEntryType.Error);
return(false);
}
// Ensure that a socket needs to be initialized.
if (_socket != null)
{
return(true);
}
// Ensure that a socket needs to be initialized and bound.
if (_socket != null && _socket.IsBound)
{
return(true);
}
try
{
_socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not create socket because: " + ex.Message, System.Diagnostics.EventLogEntryType.Error);
return(false);
}
Trace.WriteLine("Binding socket");
// Bind the socket to the specificed IP and port
try
{
_socket.Bind(new IPEndPoint(_listenAddress, _listenPort));
}
catch (Exception ex)
{
_socket.Close();
_socket = null;
EventLogger.LogEvent("Could not bind socket because: " + ex.Message, System.Diagnostics.EventLogEntryType.Error);
return(false);
}
if (_socket == null)
{
return(false);
}
// Create a new LogBuffer that will be used to store messages until they are discarded or flushed to a persistent store.
_buffer = new LogBuffer(_logBufferFlushFrequency);
if (handlers != null)
{
Trace.WriteLine("Initialising handlers");
// Load each module (handler) from the configuration file
foreach (HandlerConfiguration handler in handlers.Handlers)
{
IDictionary <string, string> properties = new Dictionary <string, string>();
handler.HandlerProperties.AllKeys.All(key =>
{
properties[key] = handler.HandlerProperties[key].Value;
return(true);
});
var msgHandler = new MessageHandler(handler.AssemblyName, handler.ParserClassName, handler.StorageClassName, handler.ConnectionString, properties);
// If the handler has a storage class then setup the buffer to temporarily store the messages
if (handler.StorageClassName != null)
{
Trace.WriteLine("Intialising buffer");
_buffer.InitHandler(msgHandler);
}
// If the handler is configured for specific IP addresses, setup the IP handler lookup list
if (!string.IsNullOrEmpty(handler.FilterIPAddresses))
{
var filters = handler.FilterIPAddresses.Split(',', ';');
foreach (var filter in filters)
{
_ipFilters.Add(filter, msgHandler);
// If the handler also has IP forwards set, add them to the IP Forwards lookup list
if (!string.IsNullOrEmpty(handler.IPForwards))
{
_ipForwards.Add(filter, handler.IPForwards.Split(',', ';'));
}
}
}
}
}
// If any handler has an IP forward setup, create a send socket that will be used forward messages
if (_ipForwards.Count > 0)
{
try
{
_sendSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
_sendSocket.Bind(new IPEndPoint(IPAddress.Any, 0));
}
catch (Exception ex)
{
}
}
Trace.WriteLine("Registering receive event");
try
{
// Start the listen operation on the socket
RegisterReceiveOperation();
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not register socket on data received event because: " + ex.Message, System.Diagnostics.EventLogEntryType.Error);
return(false);
}
return(true);
}
/// <summary>
/// Processes a message received event.
/// </summary>
/// <param name="result">The result of a receive event.</param>
private void ReceiveCallback(IAsyncResult result)
{
Trace.WriteLine("Receive callback");
// get a reference to the socket on which the message was received
Socket sock = (Socket)result.AsyncState;
EndPoint ep = null;
IPEndPoint remoteEp = null;
// variable to store received data length
int inlen;
_remoteEndpoint = new IPEndPoint(IPAddress.Any, 0);
// Gather information about the message and the sender
try
{
ep = _remoteEndpoint;
inlen = sock.EndReceiveFrom(result, ref ep);
remoteEp = (IPEndPoint)ep;
}
catch (Exception ex)
{
// only post messages if class socket reference is not null
// in all other cases, the socket has been terminated
if (_socket != null)
{
EventLogger.LogEvent("Receive operation failed with message: " + ex.Message,
System.Diagnostics.EventLogEntryType.Warning);
}
inlen = -1;
}
// if socket has been closed, ignore received data and return
if (_socket == null)
{
return;
}
// check that received data is long enough
if (inlen <= 0)
{
// request next packet
RegisterReceiveOperation();
return;
}
// If an IP forward is defined for the source of this message, forward the message to the specified IP's
if (_ipForwards.ContainsKey(remoteEp.Address.ToString()))
{
if (_socket != null)
{
foreach (string ipAddress in _ipForwards[remoteEp.Address.ToString()])
{
var sendBuffer = new byte[_receiveBuffer.Length];
_receiveBuffer.CopyTo(sendBuffer, 0);
_sendSocket.BeginSendTo(sendBuffer, 0, inlen, SocketFlags.None,
new IPEndPoint(IPAddress.Parse(ipAddress), 514), new AsyncCallback(SendCallback), _sendSocket);
}
}
}
string packet = null;
// Get the human readable text of the message to process
try
{
packet = System.Text.Encoding.ASCII.GetString(_receiveBuffer, 0, inlen);
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not parse packet to string because: " + ex.Message,
System.Diagnostics.EventLogEntryType.Warning);
}
// Run the regular expression against the message text to extract the groups
var m = _msgRegex.Match(packet);
//If a match is not found the message is not valid
if (m != null && !string.IsNullOrEmpty(packet))
{
//parse PRI section into a priority value
int pri;
var priority = int.TryParse(m.Groups["PRI"].Value, out pri) ? pri : 0;
//parse the HEADER section - contains TIMESTAMP and HOSTNAME
string hostname = null;
DateTime?timestamp = null;
// Get the timestamp and hostname from the header of the message
if (!string.IsNullOrEmpty(m.Groups["HDR"].Value))
{
if (!string.IsNullOrEmpty(m.Groups["TIMESTAMP"].Value))
{
try
{
timestamp = new DateTime(
DateTime.Now.Year,
MonthNumber(m.Groups["MMM"].Value),
int.Parse(m.Groups["DD"].Value),
int.Parse(m.Groups["HH"].Value),
int.Parse(m.Groups["MM"].Value),
int.Parse(m.Groups["SS"].Value)
);
}
catch (ArgumentException)
{
//Ignore bad timestamp args.
}
}
if (!string.IsNullOrEmpty(m.Groups["HOSTNAME"].Value))
{
hostname = m.Groups["HOSTNAME"].Value;
}
}
if (!timestamp.HasValue)
{
//add timestamp as per RFC3164
timestamp = DateTime.Now;
}
if (string.IsNullOrEmpty(hostname))
{
hostname = ep.ToString();
}
// Get the message text part of the message if it was found
if ((m.Groups["MSG"].Value) != null)
{
var message = m.Groups["MSG"].Value;
try
{
var sm = new SyslogMessage(priority, timestamp.Value, hostname, message);
// Ensure that a handler is defined for the MessageReceived event
if (MessageReceived != null)
{
Trace.WriteLine("Calling MessageReceived event");
MessageReceived(new MessageReceivedEventArgs(sm));
}
//If the message is from an IP not listed in any filter do not process it
if (!_ipFilters.ContainsKey(remoteEp.Address.ToString()))
{
Trace.WriteLine("Remote IP not listed in filter");
RegisterReceiveOperation();
return;
}
string[] parsedMsg = null;
if (_ipFilters[remoteEp.Address.ToString()].ParserClassName != null)
{
try
{
// Parse the message using the parser defined for IP from where the message came
parsedMsg = _ipFilters[remoteEp.Address.ToString()].GetParser().Parse(sm);
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not get parser or parse message for ip " + remoteEp.Address.ToString()
+ " because: " + ex.Message, System.Diagnostics.EventLogEntryType.Warning);
}
}
// Add the message to the LogBuffer if a storage Class is defined and message was parsed successfully.
if (parsedMsg != null && _buffer != null && _ipFilters[remoteEp.Address.ToString()].StorerClassName != null)
{
Trace.WriteLine("Adding message to buffer");
_buffer.AddEntry(_ipFilters[remoteEp.Address.ToString()].AssemblyName, parsedMsg);
}
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not create new SyslogMessage because: " + ex.Message,
System.Diagnostics.EventLogEntryType.Warning);
}
}
}
// Return the socket to the listen state
RegisterReceiveOperation();
}
/// <summary>
/// Creates a socket that waits for traffic and sets up the handler modules
/// </summary>
/// <returns>Returns true if the listener starts successfully. Otherwise, false.</returns>
public bool Start()
{
HandlerSection handlers;
// Get the handlers collection
try
{
handlers = (HandlerSection)System.Configuration.ConfigurationManager.GetSection("handlerSection");
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not load configuration because: " + ex.Message, System.Diagnostics.EventLogEntryType.Error);
return(false);
}
// Ensure that a socket needs to be initialized.
if (this.socket != null)
{
return(true);
}
// Ensure that a socket needs to be initialized and bound.
if (this.socket != null && this.socket.IsBound)
{
return(true);
}
try
{
this.socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not create socket because: " + ex.Message, System.Diagnostics.EventLogEntryType.Error);
return(false);
}
// Bind the socket to the specificed IP and port
try
{
this.socket.Bind(new IPEndPoint(this.listenAddress, SYSLOG_PORT));
}
catch (Exception ex)
{
this.socket.Close();
this.socket = null;
EventLogger.LogEvent("Could not bind socket because: " + ex.Message, System.Diagnostics.EventLogEntryType.Error);
return(false);
}
if (this.socket == null)
{
return(false);
}
// Create a new LogBuffer that will be used to store messages until they are discarded or flushed to a persistent store.
buffer = new LogBuffer(this.logBufferFlushFrequency);
if (handlers != null)
{
// Load each module (handler) from the configuration file
foreach (HandlerConfiguration handler in handlers.Handlers)
{
MessageHandler msgHandler = new MessageHandler(handler.AssemblyName, handler.ParserClassName,
handler.StorageClassName, handler.ConnectionString);
// If the handler has a storage class then setup the buffer to temporarily store the messages
if (handler.StorageClassName != null)
{
buffer.InitializeBuffer(msgHandler);
}
// If the handler is configured for specific IP addresses, setup the IP handler lookup list
if (handler.FilterIPAddresses != null)
{
string[] filters = handler.FilterIPAddresses.Split(',', ';');
for (int i = 0; i < filters.Length; i++)
{
ipFilters.Add(filters[i], msgHandler);
// If the handler also has IP forwards set, add them to the IP Forwards lookup list
if (handler.IPForwards != null && handler.IPForwards.Length > 0)
{
ipForwards.Add(filters[i], handler.IPForwards.Split(',', ';'));
}
}
}
}
}
// If any handler has an IP forward setup, create a send socket that will be used forward messages
if (ipForwards.Count > 0)
{
try
{
sendSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
sendSocket.Bind(new IPEndPoint(IPAddress.Any, 0));
}
catch (Exception ex)
{
}
}
try
{
// Start the listen operation on the socket
RegisterReceiveOperation();
}
catch (Exception ex)
{
EventLogger.LogEvent("Could not register socket on data received event because: " + ex.Message, System.Diagnostics.EventLogEntryType.Error);
return(false);
}
return(true);
}
