gov.nist.javax.sip.stack.CongestionControlMessageValve Maven / Gradle / Ivy
/*
* Conditions Of Use
*
* This software was developed by employees of the National Institute of
* Standards and Technology (NIST), an agency of the Federal Government.
* Pursuant to title 15 Untied States Code Section 105, works of NIST
* employees are not subject to copyright protection in the United States
* and are considered to be in the public domain. As a result, a formal
* license is not needed to use the software.
*
* This software is provided by NIST as a service and is expressly
* provided "AS IS." NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
* AND DATA ACCURACY. NIST does not warrant or make any representations
* regarding the use of the software or the results thereof, including but
* not limited to the correctness, accuracy, reliability or usefulness of
* the software.
*
* Permission to use this software is contingent upon your acceptance
* of the terms of this agreement
*
* .
*
*/
package android.gov.nist.javax.sip.stack;
import java.io.IOException;
import android.gov.nist.core.CommonLogger;
import android.gov.nist.core.StackLogger;
import android.gov.nist.javax.sip.SipStackImpl;
import android.gov.nist.javax.sip.message.SIPRequest;
import android.gov.nist.javax.sip.message.SIPResponse;
import android.javax.sip.SipStack;
import android.javax.sip.message.Request;
import android.javax.sip.message.Response;
/**
* This is just a simple reusable congestion control valve JSIP apps can use to stop traffic when the number of
* server transactions reaches the limit specified in android.gov.nist.javax.sip.MAX_SERVER_TRANSACTIONS without breaking
* existing dialogs.
*
* The drop policy is specified in DROP_RESPONSE_STATUS where "0" means silent drop and any positive number will be
* interpreted as the status code of the error response that will be generated.
*
* To enable this in your application you must specify this property:
* android.gov.nist.javax.sip.SIP_MESSAGE_VALVE=android.gov.nist.javax.sip.stack.CongestionControlMessageValve
*
* It is advised to extend this class to add your application-specific control conditions
*
* @author vladimirralev
*
*/
public class CongestionControlMessageValve implements SIPMessageValve{
private static StackLogger logger = CommonLogger.getLogger(CongestionControlMessageValve.class);
protected SipStackImpl sipStack;
// High water mark for ServerTransaction Table
// after which requests are dropped.
protected int serverTransactionTableHighwaterMark;
protected int dropResponseStatus;
public boolean processRequest(SIPRequest request,
MessageChannel messageChannel) {
String requestMethod = request.getMethod();
// We should not attempt to drop these requests because they actually free resources
// which is our goal in congested mode
boolean undropableMethod = requestMethod.equals(Request.BYE)
|| requestMethod.equals(Request.ACK)
|| requestMethod.equals(Request.PRACK)
|| requestMethod.equals(Request.CANCEL);
if(!undropableMethod) {
if(serverTransactionTableHighwaterMark <= sipStack.getServerTransactionTableSize()) {
// Allow directly any subsequent requests
if(request.getToTag() != null) {
return true;
}
if(dropResponseStatus>0) {
SIPResponse response = request.createResponse(dropResponseStatus);
try {
messageChannel.sendMessage(response);
} catch (IOException e) {
logger.logError("Failed to send congestion control error response" + response, e);
}
}
return false; // Do not pass this request to the pipeline
}
}
return true; // OK, the processing of the request can continue
}
public boolean processResponse(Response response,
MessageChannel messageChannel) {
return true;
}
public void destroy() {
logger.logInfo("Destorying the congestion control valve " + this);
}
public void init(SipStack stack) {
sipStack = (SipStackImpl) stack;
logger.logInfo("Initializing congestion control valve");
String serverTransactionsString = sipStack.getConfigurationProperties().getProperty("android.gov.nist.javax.sip.MAX_SERVER_TRANSACTIONS", "10000");
serverTransactionTableHighwaterMark = new Integer(serverTransactionsString);
String dropResponseStatusString = sipStack.getConfigurationProperties().getProperty("DROP_RESPONSE_STATUS", "503");
dropResponseStatus = new Integer(dropResponseStatusString);
}
}