/*
* JBoss, Home of Professional Open Source
* Copyright 2011, Red Hat, Inc. and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.mobicents.protocols.ss7.mtp.util;
/**
* Small class to define methods of use to o
*
* @author baranowb
*
*/
public class MTPUtility {
/**
* Extract routing information from source[], it expects that source is properly encoded routing label atleast(5bytes long,
* same as dest). It copies data to <b>dest</b> and swamp <i>DPC</i> with <i>OPC</i>.
*
* @param source
* @param dest
*/
public static void copyBackRouteHeader(byte[] source, byte[] dest) {
int thisPointCode = getFromSif_DPC(source, 1);
int remotePointCode = getFromSif_OPC(source, 1);
int sls = getFromSif_SLS(source, 1);
int si = getFromSif_SI(source);
int ssi = getFromSif_SSI(source);
writeRoutingLabel(dest, si, ssi, sls, remotePointCode, thisPointCode);
}
/**
* Retrieves DPC from SIF. SIF starts from byte 1 in MSU. For MSU [SIO,DPC,OPC,SLS,Data], call would look as following: int
* dpc = getFromSif_DPC(MSU,1);
*
* @param sif - byte[] - either SIF or MSU
* @param shift - shift in passed byte[]. For MSU its 1. For SIF part of MSU it will be 0;
* @return
*/
public static final int getFromSif_DPC(byte[] sif, int shift) {
int dpc = (sif[0 + shift] & 0xff | ((sif[1 + shift] & 0x3f) << 8));
return dpc;
}
/**
* Retrieves OPC from SIF. SIF starts from byte 1 in MSU. For MSU [SIO,DPC,OPC,SLS,Data], call would look as following: int
* opc = getFromSif_OPC(MSU,1);
*
* @param sif - byte[] - either SIF or MSU
* @param shift - shift in passed byte[]. For MSU its 1. For SIF part of MSU it will be 0;
* @return
*/
public static final int getFromSif_OPC(byte[] sif, int shift) {
int opc = ((sif[1 + shift] & 0xC0) >> 6) | ((sif[2 + shift] & 0xff) << 2) | ((sif[3 + shift] & 0x0f) << 10);
return opc;
}
/**
* Retrieves SLS from SIF. SIF starts from byte 1 in MSU. For MSU [SIO,DPC,OPC,SLS,Data], call would look as following: int
* opc = getFromSif_SLS(MSU,1);
*
* @param sif - byte[] - either SIF or MSU
* @param shift - shift in passed byte[]. For MSU its 1. For SIF part of MSU it will be 0;
* @return
*/
public static final int getFromSif_SLS(byte[] sif, int shift) {
int sls = (sif[3 + shift] & 0xf0) >>> 4;
return sls;
}
public static final int getFromSif_SI(byte[] data) {
int serviceIndicator = data[0] & 0x0f;
return serviceIndicator;
}
public static final int getFromSif_SSI(byte[] data) {
// see Q.704.14.2
int subserviceIndicator = (data[0] >> 4) & 0x0F;
return subserviceIndicator;
}
/**
* Encodes routing label into passed byte[]. It has to be at least 5 bytes long!
*
* @param destination
* @param si
* @param ssi
* @param sls
* @param dpc
* @param opc
*/
public static void writeRoutingLabel(byte[] destination, int si, int ssi, int sls, int dpc, int opc) {
// see Q.704.14.2
destination[0] = (byte) (((ssi & 0x0F) << 4) | (si & 0x0F));
destination[1] = (byte) dpc;
destination[2] = (byte) (((dpc >> 8) & 0x3F) | ((opc & 0x03) << 6));
destination[3] = (byte) (opc >> 2);
destination[4] = (byte) (((opc >> 10) & 0x0F) | ((sls & 0x0F) << 4));
// sif[4] = (byte) (((opc>> 10) & 0x0F) | ((0 & 0x0F) << 4));
}
}