/**
 * layer3.cpp
 * This file is part of the YATE Project http://YATE.null.ro
 *
 * Yet Another Signalling Stack - implements the support for SS7, ISDN and PSTN
 *
 * Yet Another Telephony Engine - a fully featured software PBX and IVR
 * Copyright (C) 2004-2014 Null Team
 *
 * This software is distributed under multiple licenses;
 * see the COPYING file in the main directory for licensing
 * information for this specific distribution.
 *
 * This use of this software may be subject to additional restrictions.
 * See the LEGAL file in the main directory for details.
 *
 * This program 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.
 */

#include "yatesig.h"
#include <yatephone.h>
#include <stdlib.h>


using namespace TelEngine;

static const TokenDict s_dict_control[] = {
    { "show",    SS7MTP3::Status },
    { "pause",   SS7MTP3::Pause },
    { "resume",  SS7MTP3::Resume },
    { "restart", SS7MTP3::Restart },
    { 0, 0 }
};

typedef GenPointer<SS7Layer2> L2Pointer;

void SS7L3User::notify(SS7Layer3* network, int sls)
{
    Debug(this,DebugStub,"Please implement SS7L3User::notify(%p,%d) [%p]",network,sls,this);
}

ObjList* SS7L3User::getNetRoutes(SS7Layer3* network, SS7PointCode::Type type)
{
    return network ? network->getRoutes(type) : (ObjList*)0;
}

const ObjList* SS7L3User::getNetRoutes(const SS7Layer3* network, SS7PointCode::Type type)
{
    return network ? network->getRoutes(type) : (const ObjList*)0;
}


// Constructor
SS7Layer3::SS7Layer3(SS7PointCode::Type type)
    : SignallingComponent("SS7Layer3"),
      m_routeMutex(true,"SS7Layer3::route"),
      m_l3userMutex(true,"SS7Layer3::l3user"),
      m_l3user(0), m_defNI(SS7MSU::National)
{
    for (unsigned int i = 0; i < YSS7_PCTYPE_COUNT; i++)
	m_local[i] = 0;
    setType(type);
}

// Initialize the Layer 3 component
bool SS7Layer3::initialize(const NamedList* config)
{
    if (config)
	setNI(SS7MSU::getNetIndicator(config->getValue(YSTRING("netindicator")),SS7MSU::National));
    if (engine() && !user()) {
	NamedList params("ss7router");
	if (!resolveConfig(YSTRING("router"),params,config))
	    params.addParam("local-config","true");
	if (params.toBoolean(true))
	    SS7Layer3::attach(YOBJECT(SS7Router,engine()->build("SS7Router",params,true,false)));
    }
    return true;
}

// Attach a Layer 3 user component to this network
void SS7Layer3::attach(SS7L3User* l3user)
{
    Lock lock(m_l3userMutex);
    if (m_l3user == l3user)
	return;
    SS7L3User* tmp = m_l3user;
    m_l3user = l3user;
    lock.drop();
    if (tmp) {
	const char* name = 0;
	if (engine() && engine()->find(tmp)) {
	    name = tmp->toString().safe();
	    if (tmp->getObject(YSTRING("SS7Router")))
		(static_cast<SS7Router*>(tmp))->detach(this);
	    else
		tmp->attach(0);
	}
	Debug(this,DebugAll,"Detached L3 user (%p,'%s') [%p]",tmp,name,this);
    }
    if (!l3user)
	return;
    Debug(this,DebugAll,"Attached L3 user (%p,'%s') [%p]",l3user,l3user->toString().safe(),this);
    insert(l3user);
    if (l3user->getObject(YSTRING("SS7Router")))
	(static_cast<SS7Router*>(l3user))->attach(this);
    else
	l3user->attach(this);
}

SS7PointCode::Type SS7Layer3::type(unsigned char netType) const
{
    if (netType & 0xc0)
	netType >>= 6;
    return m_cpType[netType & 0x03];
}

void SS7Layer3::setType(SS7PointCode::Type type, unsigned char netType)
{
    if (netType & 0xc0)
	netType >>= 6;
    m_cpType[netType & 0x03] = type;
}

void SS7Layer3::setType(SS7PointCode::Type type)
{
    m_cpType[3] = m_cpType[2] = m_cpType[1] = m_cpType[0] = type;
}

unsigned char SS7Layer3::getNI(SS7PointCode::Type pcType, unsigned char defNI) const
{
    if ((defNI & 0xc0) == 0)
	defNI <<= 6;
    if (SS7PointCode::Other == pcType || type(defNI) == pcType)
	return defNI;
    if (pcType == m_cpType[2])
	return SS7MSU::National;
    if (pcType == m_cpType[3])
	return SS7MSU::ReservedNational;
    if (pcType == m_cpType[0])
	return SS7MSU::International;
    if (pcType == m_cpType[1])
	return SS7MSU::SpareInternational;
    return defNI;
}

void SS7Layer3::setNI(unsigned char defNI)
{
    if ((defNI & 0xc0) == 0)
	defNI <<= 6;
    m_defNI = defNI & 0xc0;
}

bool SS7Layer3::hasType(SS7PointCode::Type pcType) const
{
    if (SS7PointCode::Other == pcType)
	return false;
    for (int i = 0; i < 4; i++)
	if (pcType == m_cpType[i])
	    return true;
    return false;
}

// Build the list of destination point codes and set the routing priority
bool SS7Layer3::buildRoutes(const NamedList& params)
{
    Lock lock(m_routeMutex);
    for (unsigned int i = 0; i < YSS7_PCTYPE_COUNT; i++) {
	m_route[i].clear();
	m_local[i] = 0;
    }
    unsigned int n = params.length();
    bool added = false;
    for (unsigned int i= 0; i < n; i++) {
	NamedString* ns = params.getParam(i);
	if (!ns)
	    continue;
	unsigned int prio = 0;
	unsigned int shift = 0;
	unsigned int maxLength = MAX_TDM_MSU_SIZE;
	bool local = false;
	if (ns->name() == YSTRING("local"))
	    local = true;
	else if (ns->name() == YSTRING("route"))
	    prio = 100;
	else if (ns->name() != YSTRING("adjacent"))
	    continue;
	// Get & check the route
	ObjList* route = ns->split(',',true);
	ObjList* obj = route->skipNull();
	SS7PointCode pc;
	SS7PointCode::Type type = SS7PointCode::Other;
	do {
	    if (!obj)
		break;
	    type = SS7PointCode::lookup(obj->get()->toString());
	    obj = obj->skipNext();
	    if (!(obj && pc.assign(obj->get()->toString(),type)))
		break;
	    if (prio) {
		if (!(obj = obj->skipNext()))
		    break;
		prio = obj->get()->toString().toInteger(prio);
		obj = obj->skipNext();
		if (obj)
		    shift = obj->get()->toString().toInteger(0);
	    }
	    if (!(obj = obj->skipNext()) || local)
		break;
	    maxLength = obj->get()->toString().toInteger(maxLength);
	    if (maxLength < MAX_TDM_MSU_SIZE) {
		Debug(this,DebugNote,"MaxDataLength is too small %d. Setting it to %d",
			maxLength,MAX_TDM_MSU_SIZE);
		maxLength = MAX_TDM_MSU_SIZE;
	    }
	} while (false);
	TelEngine::destruct(route);
	unsigned int packed = pc.pack(type);
	if ((unsigned int)type > YSS7_PCTYPE_COUNT || !packed) {
	    Debug(this,DebugNote,"Invalid %s='%s' (invalid point code%s) [%p]",
		ns->name().c_str(),ns->safe(),type == SS7PointCode::Other ? " type" : "",this);
	    continue;
	}
	if (local) {
	    m_local[type - 1] = packed;
	    continue;
	}
	if (findRoute(type,packed)) {
	    Debug(this,DebugWarn,"Duplicate route found %s!!",ns->c_str());
	    continue;
	}
	added = true;
	m_route[(unsigned int)type - 1].append(new SS7Route(packed,type,prio,shift,maxLength));
	DDebug(this,DebugAll,"Added route '%s'",ns->c_str());
    }
    if (!added)
	Debug(this,DebugMild,"No outgoing routes [%p]",this);
    else
	printRoutes();
    return added;
}

// Get the maximum data length that this route can transport
unsigned int SS7Layer3::getRouteMaxLength(SS7PointCode::Type type, unsigned int packedPC)
{
    if (type == SS7PointCode::Other || (unsigned int)type > YSS7_PCTYPE_COUNT || !packedPC)
	return MAX_TDM_MSU_SIZE;
    Lock lock(m_routeMutex);
    SS7Route* route = findRoute(type,packedPC);
    if (route)
	return route->m_maxDataLength;
    return MAX_TDM_MSU_SIZE;
}


// Get the priority of a route.
unsigned int SS7Layer3::getRoutePriority(SS7PointCode::Type type, unsigned int packedPC)
{
    if (type == SS7PointCode::Other || (unsigned int)type > YSS7_PCTYPE_COUNT || !packedPC)
	return (unsigned int)-1;
    Lock lock(m_routeMutex);
    SS7Route* route = findRoute(type,packedPC);
    if (route)
	return route->m_priority;
    return (unsigned int)-1;
}

// Get the state of a route.
SS7Route::State SS7Layer3::getRouteState(SS7PointCode::Type type, unsigned int packedPC, bool checkAdjacent)
{
    if (type == SS7PointCode::Other || (unsigned int)type > YSS7_PCTYPE_COUNT || !packedPC)
	return SS7Route::Unknown;
    Lock lock(m_routeMutex);
    for (ObjList* o = m_route[type-1].skipNull(); o; o = o->skipNext()) {
	SS7Route* route = static_cast<SS7Route*>(o->get());
	if (route->packed() == packedPC)
	    return route->state();
	if (checkAdjacent && !route->priority() && !(route->state() & SS7Route::NotProhibited))
	    return route->state();
    }
    return SS7Route::Unknown;
}

bool SS7Layer3::maintenance(const SS7MSU& msu, const SS7Label& label, int sls)
{
    if (msu.getSIF() != SS7MSU::MTN && msu.getSIF() != SS7MSU::MTNS)
	return false;

    // Q.707 says test pattern length should be 1-15 but we accept 0 as well
    const unsigned char* s = msu.getData(label.length()+1,2);
    if (!s)
	return false;
    String addr;
    addr << SS7PointCode::lookup(label.type()) << "," << label;
    if (debugAt(DebugAll))
	addr << " (" << label.opc().pack(label.type()) << ":" << label.dpc().pack(label.type()) << ":" << label.sls() << ")";

    unsigned int local = getLocal(label.type());
    if (local && label.dpc().pack(label.type()) != local) {
	Debug(this,DebugMild,"Received MTN %s type %02X length %u %s [%p]",
	    addr.c_str(),s[0],msu.length(),
	    (label.opc().pack(label.type()) == local ? "looped back!" : "with invalid DPC"),
	    this);
	return false;
    }

    bool badLink = label.sls() != sls;
    if (!badLink) {
	unsigned int local = getLocal(label.type());
	// maintenance messages must be addressed to us
	if (local && label.dpc().pack(label.type()) != local)
	    badLink = true;
	// and come from an adjacent node
	else if (getRoutePriority(label.type(),label.opc()))
	    badLink = true;
    }
    int level = DebugAll;
    if (getNI(type(msu.getNI())) != msu.getNI()) {
	addr << " wrong " << msu.getIndicatorName() << " NI";
	level = DebugMild;
    }
    if (badLink) {
	addr << " on " << sls;
	level = DebugWarn;
    }
    unsigned char len = s[1] >> 4;
    // get a pointer to the test pattern
    const unsigned char* t = msu.getData(label.length()+3,len);
    if (!t) {
	Debug(this,DebugMild,"Received MTN %s type %02X length %u with invalid pattern length %u [%p]",
	    addr.c_str(),s[0],msu.length(),len,this);
	return false;
    }
    switch (s[0]) {
	case SS7MsgMTN::SLTM:
	    Debug(this,level,"Received SLTM %s with %u bytes",addr.c_str(),len);
	    if (badLink)
		return false;
	    if (responder()) {
		SS7Label lbl(label,label.sls(),0);
		SS7MSU answer(msu.getSIO(),lbl,0,len+2);
		unsigned char* d = answer.getData(lbl.length()+1,len+2);
		if (!d)
		    return false;
		linkChecked(sls,true);
		addr.clear();
		addr << SS7PointCode::lookup(lbl.type()) << "," << lbl;
		if (debugAt(DebugAll))
		    addr << " (" << lbl.opc().pack(lbl.type()) << ":" << lbl.dpc().pack(lbl.type()) << ":" << lbl.sls() << ")";
		Debug(this,level,"Sending SLTA %s with %u bytes",addr.c_str(),len);
		*d++ = SS7MsgMTN::SLTA;
		*d++ = len << 4;
		while (len--)
		    *d++ = *t++;
		return transmitMSU(answer,lbl,sls) >= 0;
	    }
	    return true;
	case SS7MsgMTN::SLTA:
	    Debug(this,level,"Received SLTA %s with %u bytes",addr.c_str(),len);
	    if (badLink)
		return false;
	    if (len != 4)
		return false;
	    unsigned char patt = sls;
	    patt = (patt << 4) | (patt & 0x0f);
	    while (len--)
		if (*t++ != patt++)
		    return false;
	    linkChecked(sls,false);
	    return true;
    }
    Debug(this,DebugMild,"Received MTN %s type %02X, length %u [%p]",
	addr.c_str(),s[0],msu.length(),this);
    return false;
}

bool SS7Layer3::management(const SS7MSU& msu, const SS7Label& label, int sls)
{
    if (msu.getSIF() != SS7MSU::SNM)
	return false;
    Debug(this,DebugStub,"Please implement SS7Layer3::management(%p,%p,%d) [%p]",
	&msu,&label,sls,this);
    // according to Q.704 there should be at least the heading codes (8 bit)
    const unsigned char* s = msu.getData(label.length()+1,1);
    if (!s)
	return false;
    // TODO: implement
    return false;
}

bool SS7Layer3::unavailable(const SS7MSU& msu, const SS7Label& label, int sls, unsigned char cause)
{
    DDebug(this,DebugInfo,"SS7Layer3::unavailable(%p,%p,%d,%d) [%p]",
	&msu,&label,sls,cause,this);
#ifdef DEBUG
    String s;
    s.hexify(msu.data(),msu.length(),' ');
    Debug(this,DebugMild,"Unhandled MSU len=%u Serv: %s, Prio: %s, Net: %s, Data: %s",
	msu.length(),msu.getServiceName(),msu.getPriorityName(),
	msu.getIndicatorName(),s.c_str());
#endif
    if (msu.getSIF() == SS7MSU::SNM)
	return false;
    // send a SNM UPU (User Part Unavailable, Q.704 15.17.2)
    unsigned char llen = SS7PointCode::length(label.type());
    SS7Label lbl(label,label.sls(),0);
    unsigned int local = getLocal(label.type());
    if (local)
	lbl.opc().unpack(label.type(),local);
    SS7MSU answer(SS7MSU::SNM,msu.getSSF(),lbl,0,llen+2);
    unsigned char* d = answer.getData(lbl.length()+1,llen+2);
    if (!d)
	return false;
    d[0] = SS7MsgSNM::UPU;
    label.dpc().store(label.type(),d+1);
    d[llen+1] = msu.getSIF() | ((cause & 0x0f) << 4);
    return transmitMSU(answer,lbl,sls) >= 0;
}

bool SS7Layer3::prohibited(unsigned char ssf, const SS7Label& label, int sls)
{
    DDebug(this,DebugInfo,"SS7Layer3::prohibited(%u,%p,%d) [%p]",
	ssf,&label,sls,this);
    // send a SNM TFP (Transfer Prohibited, Q.704 13.2)
    unsigned char llen = SS7PointCode::length(label.type());
    SS7Label lbl(label,label.sls(),0);
    unsigned int local = getLocal(label.type());
    if (local)
	lbl.opc().unpack(label.type(),local);
    SS7MSU answer(SS7MSU::SNM,ssf,lbl,0,llen+1);
    unsigned char* d = answer.getData(lbl.length()+1,llen+1);
    if (!d)
	return false;
    d[0] = SS7MsgSNM::TFP;
    label.dpc().store(label.type(),d+1);
    return transmitMSU(answer,lbl,sls) >= 0;
}

// Find a route having the specified point code type and packed point code
SS7Route* SS7Layer3::findRoute(SS7PointCode::Type type, unsigned int packed)
{
    if ((unsigned int)type == 0 || !packed)
	return 0;
    unsigned int index = (unsigned int)type - 1;
    if (index >= YSS7_PCTYPE_COUNT)
	return 0;
    Lock lock(m_routeMutex);
    for (ObjList* o = m_route[index].skipNull(); o; o = o->skipNext()) {
	SS7Route* route = static_cast<SS7Route*>(o->get());
	if (route->packed() == packed)
	    return route;
    }
    return 0;
}

void SS7Layer3::printRoutes()
{
    String s;
    bool router = getObject(YSTRING("SS7Router")) != 0;
    for (unsigned int i = 0; i < YSS7_PCTYPE_COUNT; i++) {
	ObjList* o = m_route[i].skipNull();
	if (!o)
	    continue;
	SS7PointCode::Type type = (SS7PointCode::Type)(i + 1);
	String tmp;
	String sType = SS7PointCode::lookup(type);
	sType << String(' ',(unsigned int)(8 - sType.length()));
	if (m_local[i])
	    sType << SS7PointCode(type,m_local[i]) << " > ";
	for (; o; o = o->skipNext()) {
	    SS7Route* route = static_cast<SS7Route*>(o->get());
	    tmp << sType << SS7PointCode(type,route->m_packed);
	    if (!router) {
		tmp << " " << route->m_priority << " (" << route->stateName() << ")";
		if (route->shift())
		    tmp << " >> " << route->shift();
		tmp << "\r\n";
		continue;
	    }
	    tmp << " (" << route->stateName() << ")";
	    for (ObjList* oo = route->m_networks.skipNull(); oo; oo = oo->skipNext()) {
		GenPointer<SS7Layer3>* d = static_cast<GenPointer<SS7Layer3>*>(oo->get());
		if (*d)
		    tmp << " " << (*d)->toString() << "," <<
			(*d)->getRoutePriority(type,route->m_packed) << "," <<
			SS7Route::stateName((*d)->getRouteState(type,route->m_packed));
	    }
	    if (route->shift())
		tmp << " >> " << route->shift();
	    tmp << "\r\n";
	}
	s << tmp;
    }
    if (s) {
	s = s.substr(0,s.length() - 2);
	Output("%s of '%s': [%p]\r\n%s",router?"Routing table":"Destinations",debugName(),this,s.c_str());
    }
    else
	Output("No %s in '%s' [%p]",router?"routes":"destinations",debugName(),this);
}


SS7MTP3::SS7MTP3(const NamedList& params)
    : SignallingComponent(params.safe("SS7MTP3"),&params,"ss7-mtp3"),
      SignallingDumpable(SignallingDumper::Mtp3),
      Mutex(true,"SS7MTP3"),
      m_total(0), m_active(0), m_slcShift(false), m_inhibit(false), m_warnDown(true),
      m_checklinks(true), m_forcealign(true), m_checkT1(0), m_checkT2(0)
{
#ifdef DEBUG
    if (debugAt(DebugAll)) {
	String tmp;
	params.dump(tmp,"\r\n  ",'\'',true);
	Debug(this,DebugAll,"SS7MTP3::SS7MTP3(%p) [%p]%s",
	    &params,this,tmp.c_str());
    }
#endif
    for (unsigned int i = 0; i < YSS7_PCTYPE_COUNT; i++)
	m_allowed[i] = 0;
    // Set point code type for each network indicator
    static const unsigned char ni[4] = { SS7MSU::International,
	SS7MSU::SpareInternational, SS7MSU::National, SS7MSU::ReservedNational };
    String stype = params.getValue(YSTRING("netind2pctype"));
    int level = DebugAll;
    if (stype.find(',') >= 0) {
	ObjList* obj = stype.split(',',false);
	ObjList* o = obj->skipNull();
	for (unsigned int i = 0; i < 4; i++) {
	    String* s = 0;
	    if (o) {
		s = static_cast<String*>(o->get());
		o = o->skipNext();
	    }
	    SS7PointCode::Type type = SS7PointCode::lookup(s?s->c_str():0);
	    if (type == SS7PointCode::Other)
		level = DebugNote;
	    setType(type,ni[i]);
	}
	TelEngine::destruct(obj);
    }
    else {
	SS7PointCode::Type type = SS7PointCode::lookup(stype.c_str());
	if (type == SS7PointCode::Other)
	    level = DebugNote;
	for (unsigned int i = 0; i < 4; i++)
	    setType(type,ni[i]);
    }
    Debug(this,level,"Point code types are '%s' [%p]",stype.safe(),this);

    m_slcShift = params.getBoolValue(YSTRING("slcshift"),false);
    m_inhibit = !params.getBoolValue(YSTRING("autostart"),true);
    m_checklinks = params.getBoolValue(YSTRING("checklinks"),m_checklinks);
    m_forcealign = params.getBoolValue(YSTRING("forcealign"),m_forcealign);
    int check = params.getIntValue(YSTRING("checkfails"),5000);
    if (check > 0) {
	if (check < 4000)
	    check = 4000;
	else if (check > 12000)
	    check = 12000;
	m_checkT1 = 1000 * check;
    }
    check = params.getIntValue(YSTRING("maintenance"),60000);
    if (check > 0) {
	if (check < 30000)
	    check = 30000;
	else if (check > 300000)
	    check = 300000;
	m_checkT2 = 1000 * check;
    }
    buildRoutes(params);
    unsigned int n = params.length();
    for (unsigned int p = 0; p < n; p++) {
	NamedString* ns = params.getParam(p);
	if (!ns || (ns->name() != "allowed"))
	    continue;
	ObjList* l = ns->split(',',false);
	ObjList* o = l->skipNull();
	if (o) {
	    SS7PointCode::Type type = SS7PointCode::lookup(o->get()->toString());
	    o = o->skipNext();
	    if (o && (SS7PointCode::Other != type)) {
		unsigned int a = o->count();
		delete[] m_allowed[type-1];
		m_allowed[type-1] = new unsigned int[a+1];
		for (a = 0; o; o = o->skipNext())
		    m_allowed[type-1][a++] = o->get()->toString().toInteger(-1);
		m_allowed[type-1][a] = 0;
	    }
	}
	TelEngine::destruct(l);
    }
    setDumper(params.getValue(YSTRING("layer3dump")));
}

SS7MTP3::~SS7MTP3()
{
    setDumper();
    for (unsigned int i = 0; i < YSS7_PCTYPE_COUNT; i++)
	delete[] m_allowed[i];
}

unsigned int SS7MTP3::countLinks()
{
    unsigned int total = 0;
    unsigned int checked = 0;
    unsigned int active = 0;
    ObjList* l = &m_links;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!(p && *p))
	    continue;
	total++;
	if ((*p)->operational()) {
	    if (!((*p)->inhibited(SS7Layer2::Unchecked))) {
		checked++;
		if (!((*p)->inhibited()))
		    active++;
	    }
	}
    }
    m_total = total;
    m_checked = checked;
    m_active = active;
    return active;
}

bool SS7MTP3::operational(int sls) const
{
    if (m_inhibit)
	return false;
    if (sls < 0)
	return (m_active != 0);
    const ObjList* l = &m_links;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!(p && *p))
	    continue;
	if ((*p)->sls() == sls)
	    return (*p)->operational();
    }
    return false;
}

int SS7MTP3::inhibited(int sls) const
{
    if (sls < 0)
	return m_inhibit ? SS7Layer2::Inactive : 0;
    const ObjList* l = &m_links;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!(p && *p))
	    continue;
	if ((*p)->sls() == sls)
	    return (*p)->inhibited();
    }
    return SS7Layer2::Inactive;
}

bool SS7MTP3::inhibit(int sls, int setFlags, int clrFlags)
{
    if (sls < 0)
	return false;
    const ObjList* l = &m_links;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!(p && *p))
	    continue;
	if ((*p)->sls() == sls) {
	    DDebug(this,DebugAll,"Setting inhibition +0x%02X -0x%02X on %d '%s' [%p]",
		setFlags,clrFlags,sls,(*p)->toString().c_str(),this);
	    return (*p)->inhibit(setFlags,clrFlags);
	}
    }
    return false;
}

unsigned int SS7MTP3::congestion(int sls)
{
    unsigned int level = 0;
    const ObjList* l = &m_links;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!(p && *p))
	    continue;
	if ((*p)->sls() == sls)
	    return (*p)->congestion();
	else if (sls >= 0) {
	    unsigned int cong = (*p)->congestion();;
	    if (level < cong)
		level = cong;
	}
    }
    return level;
}

int SS7MTP3::getSequence(int sls) const
{
    if (sls < 0)
	return -1;
    const ObjList* l = &m_links;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!(p && *p))
	    continue;
	if ((*p)->sls() == sls)
	    return (*p)->getSequence();
    }
    return false;
}

void SS7MTP3::recoverMSU(int sls, int sequence)
{
    if (sls < 0)
	return;
    const ObjList* l = &m_links;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!(p && *p))
	    continue;
	if ((*p)->sls() == sls) {
	    (*p)->recoverMSU(sequence);
	    break;
	}
    }
}

// Attach a link in the first free SLS
void SS7MTP3::attach(SS7Layer2* link)
{
    if (!link)
	return;
    SignallingComponent::insert(link);
    Lock lock(this);
    // Check if already attached
    for (ObjList* o = m_links.skipNull(); o; o = o->skipNext()) {
	L2Pointer* p = static_cast<L2Pointer*>(o->get());
	if (*p == link) {
	    link->attach(this);
	    return;
	}
    }
    ObjList* before = 0;
    int sls = link->sls();
    if (sls >= 0) {
	before = m_links.skipNull();
	for (; before; before = before->skipNext()) {
	    L2Pointer* p = static_cast<L2Pointer*>(before->get());
	    if (!*p)
		continue;
	    if (sls < (*p)->sls())
		break;
	    if (sls == (*p)->sls()) {
		sls = -1;
		break;
	    }
	}
    }
    if (sls < 0) {
	// Attach in the first free SLS
	sls = 0;
	before = m_links.skipNull();
	for (; before; before = before->skipNext()) {
	    L2Pointer* p = static_cast<L2Pointer*>(before->get());
	    if (!*p)
		continue;
	    if (sls < (*p)->sls())
		break;
	    sls++;
	}
	link->sls(sls);
    }
    link->ref();
    if (!before)
	m_links.append(new L2Pointer(link));
    else
	before->insert(new L2Pointer(link));
    Debug(this,DebugAll,"Attached link (%p,'%s') with SLS=%d [%p]",
	link,link->toString().safe(),link->sls(),this);
    countLinks();
    link->attach(this);
}

// Detach a link. Remove its L2 user
void SS7MTP3::detach(SS7Layer2* link)
{
    if (!link)
	return;
    Lock lock(this);
    for (ObjList* o = m_links.skipNull(); o; o = o->skipNext()) {
	L2Pointer* p = static_cast<L2Pointer*>(o->get());
	if (*p != link)
	    continue;
	m_links.remove(p);
	Debug(this,DebugAll,"Detached link (%p,'%s') with SLS=%d [%p]",
	    link,link->toString().safe(),link->sls(),this);
	link->attach(0);
	TelEngine::destruct(link);
	countLinks();
	return;
    }
}

bool SS7MTP3::allowedTo(SS7PointCode::Type type, unsigned int packedPC) const
{
    if (type >= SS7PointCode::DefinedTypes)
	return false;
    if (!m_allowed[type-1])
	return true;
    for (int i = 0; m_allowed[type-1][i]; i++) {
	if (packedPC == m_allowed[type-1][i])
	    return true;
    }
    return false;
}

bool SS7MTP3::control(Operation oper, NamedList* params)
{
    bool ok = operational();
    if (params) {
	// cannot change SLS to SLC shift while active
	if (m_active == 0)
	    m_slcShift = params->getBoolValue(YSTRING("slcshift"),m_slcShift);
	m_checklinks = params->getBoolValue(YSTRING("checklinks"),m_checklinks);
	m_forcealign = params->getBoolValue(YSTRING("forcealign"),m_forcealign);
	const String& inh = (*params)[YSTRING("inhibit")];
	if (inh) {
	    // inhibit=slc,[inh_flags][,uninh_flags]
	    ObjList* l = inh.split(',',true);
	    if (l && (l->length() == 2 || l->length() == 3)) {
		int slc = l->at(0)->toString().toInteger(-1);
		if (slc >= 0) {
		    int inh = l->at(1)->toString().toInteger(0);
		    int unh = l->at(2) ? l->at(2)->toString().toInteger(0) : 0;
		    inhibit(slc,inh,unh);
		}
	    }
	    TelEngine::destruct(l);
	}
    }
    switch (oper) {
	case Pause:
	    if (!m_inhibit) {
		m_inhibit = true;
		if (ok)
		    SS7Layer3::notify(-1);
	    }
	    return TelEngine::controlReturn(params,true);
	case Restart:
	    if (ok) {
		ok = false;
		m_inhibit = true;
		SS7Layer3::notify(-1);
	    }
	    // fall through
	case Resume:
	    if (m_inhibit) {
		m_inhibit = false;
		if (ok != operational())
		    SS7Layer3::notify(-1);
	    }
	    m_warnDown = true;
	    if (params && params->getBoolValue(YSTRING("emergency"))) {
		unsigned int cnt = 0;
		const ObjList* l = &m_links;
		for (; l; l = l->next()) {
		    L2Pointer* p = static_cast<L2Pointer*>(l->get());
		    if (!(p && *p))
			continue;
		    cnt++;
		    (*p)->control(SS7Layer2::Resume,params);
		}
		Debug(this,DebugNote,"Emergency resume attempt on %u links [%p]",cnt,this);
	    }
	    return TelEngine::controlReturn(params,true);
	case Status:
	    printRoutes();
	    return TelEngine::controlReturn(params,ok);;
    }
    return TelEngine::controlReturn(params,false);
}

bool SS7MTP3::control(NamedList& params)
{
    String* ret = params.getParam(YSTRING("completion"));
    const String* oper = params.getParam(YSTRING("operation"));
    const char* cmp = params.getValue(YSTRING("component"));
    int cmd = oper ? oper->toInteger(s_dict_control,-1) : -1;
    if (ret) {
	if (oper && (cmd < 0))
	    return false;
	String part = params.getValue(YSTRING("partword"));
	if (cmp) {
	    if (toString() != cmp)
		return false;
	    for (const TokenDict* d = s_dict_control; d->token; d++)
		Module::itemComplete(*ret,d->token,part);
	    return true;
	}
	return Module::itemComplete(*ret,toString(),part);
    }
    if (!(cmp && toString() == cmp))
	return false;
    if (cmd >= 0)
	return control((Operation)cmd,&params);
    return SignallingDumpable::control(params,this);
}

// Configure and initialize MTP3 and its links
bool SS7MTP3::initialize(const NamedList* config)
{
#ifdef DEBUG
    String tmp;
    if (config && debugAt(DebugAll))
	config->dump(tmp,"\r\n  ",'\'',true);
    Debug(this,DebugInfo,"SS7MTP3::initialize(%p) [%p]%s",config,this,tmp.c_str());
#endif
    if (config)
	debugLevel(config->getIntValue(YSTRING("debuglevel_mtp3"),
	    config->getIntValue(YSTRING("debuglevel"),-1)));
    countLinks();
    m_warnDown = true;
    if (config && (0 == m_total)) {
	m_slcShift = config->getBoolValue(YSTRING("slcshift"),m_slcShift);
	m_checklinks = config->getBoolValue(YSTRING("checklinks"),m_checklinks);
	m_forcealign = config->getBoolValue(YSTRING("forcealign"),m_forcealign);
	unsigned int n = config->length();
	for (unsigned int i = 0; i < n; i++) {
	    NamedString* param = config->getParam(i);
	    if (!(param && param->name() == YSTRING("link")))
		continue;
	    NamedPointer* ptr = YOBJECT(NamedPointer,param);
	    NamedList* linkConfig = ptr ? YOBJECT(NamedList,ptr->userData()) : 0;
	    String linkName(*param);
	    int linkSls = -1;
	    int sep = linkName.find(',');
	    if (sep >= 0) {
		linkSls = linkName.substr(sep + 1).toInteger(-1);
		linkName = linkName.substr(0,sep);
	    }
	    NamedList params(linkName);
	    params.addParam("basename",linkName);
	    if (linkConfig)
		params.copyParams(*linkConfig);
	    else {
		if (config->hasSubParams(params + "."))
		    params.copySubParams(*config,params + ".");
		else
		    params.addParam("local-config","true");
		linkConfig = &params;
	    }
	    SS7Layer2* link = YSIGCREATE(SS7Layer2,&params);
	    if (!link)
		continue;
	    if (linkSls >= 0)
		link->sls(linkSls);
	    if (m_checklinks)
		link->inhibit(SS7Layer2::Unchecked|SS7Layer2::Inactive);
	    attach(link);
	    if (!link->initialize(linkConfig))
		detach(link);
	    TelEngine::destruct(link);
	}
	m_inhibit = !config->getBoolValue(YSTRING("autostart"),true);
    }
    SS7Layer3::initialize(config);
    return 0 != m_total;
}

// Detach all links and user. Destroys the object, disposes the memory
void SS7MTP3::destroyed()
{
    lock();
    ListIterator iter(m_links);
    for (GenObject* o = 0; 0 != (o = iter.get());) {
	L2Pointer* p = static_cast<L2Pointer*>(o);
	detach(*p);
    }
    SS7Layer3::attach(0);
    unlock();
    SS7Layer3::destroyed();
}

int SS7MTP3::transmitMSU(const SS7MSU& msu, const SS7Label& label, int sls)
{
    bool maint = (msu.getSIF() == SS7MSU::MTN) || (msu.getSIF() == SS7MSU::MTNS);
    bool mgmt = (msu.getSIF() == SS7MSU::SNM);
    bool regular = !maint && !mgmt;
    Lock lock(this);
    if (!(maint || m_active || (mgmt && m_checked))) {
	if (m_warnDown) {
	    m_warnDown = false;
	    Debug(this,m_total ? DebugInfo : DebugMild,"Could not transmit %s MSU, %s",
		msu.getServiceName(),
		m_total ? "all links are down" : "no data links attached");
	}
	return -1;
    }

    // TODO: support ranges with holes
    if (regular && sls >= 0) {
	if (m_slcShift)
	    sls = sls >> 1;
	sls = sls % m_total;
    }

    // Try to find a link with the given SLS
    ObjList* l = (sls >= 0) ? &m_links : 0;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!(p && *p))
	    continue;
	SS7Layer2* link = *p;
	if (link->sls() == sls) {
	    XDebug(this,DebugAll,"Found link %p for SLS=%d [%p]",link,sls,this);
	    if (link->operational() && (maint || !link->inhibited())) {
		if (link->transmitMSU(msu)) {
		    DDebug(this,DebugAll,"Sent MSU over link '%s' %p with SLS=%d%s [%p]",
			link->toString().c_str(),link,sls,
			(m_inhibit ? " while inhibited" : ""),this);
		    dump(msu,true,sls);
		    m_warnDown = true;
		    return (regular && m_slcShift) ? (sls << 1) : sls;
		}
		return -1;
	    }
	    if (maint) {
		Debug(this,DebugNote,"Dropping maintenance MSU for SLS=%d, link is down",sls);
		return -1;
	    }
	    // found link but is down - reroute
	    Debug(this,DebugAll,"Rerouting %s MSU for SLS=%d, link is down",
		msu.getServiceName(),sls);
	    break;
	}
    }
    if (maint)
	return -1;

    // Link not found or not operational: choose another one
    for (l = m_links.skipNull(); l; l = l->skipNext()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!*p)
	    continue;
	SS7Layer2* link = *p;
	// if we are desperate use even inhibited (but checked) links
	bool inh = (mgmt && (sls == -2)) ? link->inhibited(SS7Layer2::Unchecked) : (link->inhibited() != 0);
	if (link->operational() && !inh && link->transmitMSU(msu)) {
	    sls = link->sls();
	    DDebug(this,DebugAll,"Sent MSU over link '%s' %p with SLS=%d%s [%p]",
		link->toString().c_str(),link,sls,
		(m_inhibit ? " while inhibited" : ""),this);
	    dump(msu,true,sls);
	    m_warnDown = true;
	    return (regular && m_slcShift) ? (sls << 1) : sls;
	}
    }

    Debug(this,((sls == -2) ? DebugWarn : DebugInfo),
	"Could not find any link to send %s MSU",msu.getServiceName());
    return -1;
}

bool SS7MTP3::receivedMSU(const SS7MSU& msu, SS7Layer2* link, int sls)
{
    dump(msu,false,sls);
    int netType = msu.getNI();
    SS7PointCode::Type cpType = type(netType);
    unsigned int llen = SS7Label::length(cpType);
    if (!llen) {
	Debug(toString(),DebugWarn,"Received %s MSU, point code type unknown [%p]",
	    msu.getIndicatorName(),this);
	return false;
    }
    // check MSU length against SIO + label length
    if (msu.length() <= llen) {
	Debug(this,DebugMild,"Received on %d short MSU of length %u [%p]",
	    sls,msu.length(),this);
	return false;
    }
    SS7Label label(cpType,msu);
#ifdef DEBUG
    if (debugAt(DebugInfo)) {
	String tmp;
	tmp << label << " (" << label.opc().pack(cpType) << ":" << label.dpc().pack(cpType) << ":" << label.sls() << ")";
	Debug(this,DebugAll,"Received MSU from link %d '%s' %p. Address: %s",
	    sls,link->toString().c_str(),link,tmp.c_str());
    }
#endif
    bool maint = (msu.getSIF() == SS7MSU::MTN) || (msu.getSIF() == SS7MSU::MTNS);
    if (link && !maint) {
	int inhibited = link->inhibited() & (SS7Layer2::Unchecked|SS7Layer2::Inactive|SS7Layer2::Local);
	if (inhibited & SS7Layer2::Unchecked)
	    return false;
	if (inhibited && msu.getSIF() != SS7MSU::SNM) {
	    if (inhibited == SS7Layer2::Inactive) {
		Debug(this,DebugNote,"Activating inactive link %d '%s' on %s MSU receive",
		    sls,link->toString().c_str(),msu.getServiceName());
		link->inhibit(0,SS7Layer2::Inactive);
	    }
	    else {
		Debug(this,DebugMild,"Received MSU on inhibited 0x%02X link %d '%s'",
		    link->inhibited(),sls,link->toString().c_str());
		return false;
	    }
	}
    }
    // first try to call the user part
    HandledMSU handled = SS7Layer3::receivedMSU(msu,label,sls);
    XDebug(this,DebugAll,"MSU handling result: %u [%p]",(unsigned int)handled,this);
    switch (handled) {
	case HandledMSU::Accepted:
	case HandledMSU::Failure:
	case HandledMSU::NoCircuit:
	    return true;
	default:
	    break;
    }
    // then try to minimally process MTN and SNM MSUs
    if (maintenance(msu,label,sls) || management(msu,label,sls))
	return true;
    // either maintenance type cannot be processed more
    if (maint)
	return false;
    switch (handled) {
	case HandledMSU::NoAddress:
	    while (SS7Router* router = YOBJECT(SS7Router,user())) {
		RefPointer<SS7Management> mngmt = router->getManagement();
		if (!mngmt)
		    break;
		NamedList* ctl = mngmt->controlCreate("prohibit");
		if (!ctl)
		    break;
		unsigned int local = getLocal(cpType);
		if (!local)
		    local = label.dpc().pack(cpType);
		String addr;
		addr << SS7PointCode::lookup(cpType) << ",";
		addr << SS7PointCode(cpType,local) << "," << label.opc();
		String dest;
		dest << label.dpc();
		ctl->addParam("address",addr);
		ctl->addParam("destination",dest);
		ctl->setParam("automatic",String::boolText(true));
		return mngmt->controlExecute(ctl);
	    }
	    return prohibited(msu.getSSF(),label,sls);
	default:
	    // if nothing worked, report the unavailable regular user part
	    return (msu.getSIF() != SS7MSU::SNM) && unavailable(msu,label,sls,handled.upu());
    }
}

bool SS7MTP3::recoveredMSU(const SS7MSU& msu, SS7Layer2* link, int sls)
{
    int netType = msu.getNI();
    SS7PointCode::Type cpType = type(netType);
    unsigned int llen = SS7Label::length(cpType);
    if (!llen) {
	Debug(toString(),DebugWarn,"Recovered MSU but point code type is unconfigured [%p]",this);
	return false;
    }
    // check MSU length against SIO + label length
    if (msu.length() <= llen) {
	Debug(this,DebugWarn,"Recovered short MSU of length %u [%p]",
	    msu.length(),this);
	return false;
    }
    SS7Label label(cpType,msu);
#ifdef DEBUG
    if (debugAt(DebugInfo)) {
	String tmp;
	tmp << label << " (" << label.opc().pack(cpType) << ":" << label.dpc().pack(cpType) << ":" << label.sls() << ")";
	Debug(this,DebugAll,"Recovered MSU from link %d '%s' %p. Address: %s",
	    sls,link->toString().c_str(),link,tmp.c_str());
    }
#endif
    // first try to send on another active link in the linkset
    if (transmitMSU(msu,label,sls % m_total) >= 0)
	return true;
    return SS7Layer3::recoveredMSU(msu,label,sls);
}

void SS7MTP3::notify(SS7Layer2* link)
{
    Lock mylock(this);
    unsigned int chk = m_checked;
    unsigned int act = m_active;
    if (link) {
	if (link->operational()) {
	    if (link->inhibited(SS7Layer2::Unchecked)) {
		// initiate a slightly delayed SLTM check
		u_int64_t t = Time::now() + 100000 + (Random::random() % 200000);
		if ((link->m_checkTime > t) || (t - 2000000 > link->m_checkTime))
		    link->m_checkTime = t;
	    }
	}
	else {
	    if (m_checklinks)
		link->inhibit(SS7Layer2::Unchecked,0);
	    else
		link->inhibit(0,SS7Layer2::Unchecked);
	}
    }
    countLinks();
    String text;
    text << "Linkset has " << m_active << " active, ";
    text << m_checked << " checked of " << m_total << " links";
#ifdef DEBUG
    String tmp;
    if (link)
	tmp << "Link '" << link->toString() << "' is " << (link->operational()?"":"not ") << "operational. ";
    Debug(this,DebugInfo,"%s%s [%p]",tmp.safe(),text.c_str(),this);
#endif
    // if operational status of a link changed notify upper layer
    if (act != m_active || chk != m_checked) {
	Debug(this,DebugNote,"Linkset is%s operational [%p]",
	    (operational() ? "" : " not"),this);
	// if we became inaccessible try to uninhibit or resume all other links
	const ObjList* l = 0;
	// if a link became inactive or unchecked start emergency procedures
	if (!m_active && (act || (m_checked < chk)))
	    l = &m_links;
	unsigned int cnt = 0;
	for (; l && !(m_active || m_inhibit); l = l->next()) {
	    L2Pointer* p = static_cast<L2Pointer*>(l->get());
	    if (!p)
		continue;
	    SS7Layer2* l2 = *p;
	    if ((l2 == link) || !l2)
		continue;
	    cnt++;
	    if (l2->operational() &&
		l2->inhibited(SS7Layer2::Local|SS7Layer2::Remote) &&
		!l2->inhibited(SS7Layer2::Unchecked|SS7Layer2::Inactive)) {
		SS7Router* router = YOBJECT(SS7Router,user());
		if (!router) {
		    Debug(this,DebugMild,"No router, uninhibiting link %d '%s' [%p]",
			l2->sls(),l2->toString().c_str(),this);
		    l2->inhibit(0,SS7Layer2::Local|SS7Layer2::Remote);
		    continue;
		}
		if (l2->inhibited(SS7Layer2::Local))
		    router->uninhibit(this,l2->sls(),false);
		if (l2->inhibited(SS7Layer2::Remote))
		    router->uninhibit(this,l2->sls(),true);
	    }
	    else
		l2->control(SS7Layer2::Resume);
	}
	if (cnt)
	    Debug(this,DebugNote,"Attempted to uninhibit/resume %u links [%p]",cnt,this);

	int sls = link ? link->sls() : -1;
	NamedList notif("");
	notif.addParam("from", toString());
	notif.addParam("type","ss7-mtp3");
	notif.addParam("operational",String::boolText(operational()));
	notif.addParam("active",String(m_active));
	notif.addParam("total",String(m_total));
	notif.addParam("link", link ? link->toString() : "");
	notif.addParam("linkup", link ? String::boolText(link->operational()) : "");
	notif.addParam("text", text);
	mylock.drop();
	SS7Layer3::notify(sls);
	engine()->notify(this,notif);
    }
}

void SS7MTP3::timerTick(const Time& when)
{
    Lock mylock(this,SignallingEngine::maxLockWait());
    if (!mylock.locked())
	return;
    for (ObjList* o = m_links.skipNull(); o; o = o->skipNext()) {
	L2Pointer* p = static_cast<L2Pointer*>(o->get());
	if (!p)
	    continue;
	SS7Layer2* l2 = *p;
	if (l2 && l2->m_checkTime && (l2->m_checkTime < when) && l2->operational()) {
	    l2->m_checkTime = 0;
	    int level = DebugAll;
	    u_int64_t check = m_checkT2;
	    if (l2->m_checkFail > 1) {
		bool takeOOS = !l2->inhibited(SS7Layer2::Unchecked);
		if (takeOOS || m_forcealign) {
		    if (takeOOS)
			Debug(this,DebugWarn,"Taking link %d '%s' out of service [%p]",
			    l2->sls(),l2->toString().c_str(),this);
		    else if (m_forcealign)
			Debug(this,DebugNote,"Cycling not in service link %d '%s' [%p]",
			    l2->sls(),l2->toString().c_str(),this);
		    if (m_checkT1)
			check = m_checkT1;
		    int cycle = 0;
		    if (m_forcealign) {
			cycle = SS7Layer2::Inactive;
			l2->m_checkFail = 0;
		    }
		    l2->inhibit(SS7Layer2::Unchecked | cycle,cycle);
		}
	    }
	    else if (m_checkT1) {
		if (l2->m_checkFail++)
		    level = DebugInfo;
		check = m_checkT1;
	    }
	    // if some action set a new timer bail out, we'll get back to it
	    if (l2->m_checkTime || !l2->operational())
		continue;
	    l2->m_checkTime = check ? when + check : 0;
	    for (unsigned int i = 0; i < YSS7_PCTYPE_COUNT; i++) {
		SS7PointCode::Type type = (SS7PointCode::Type)(i + 1);
		unsigned int local = getLocal(type);
		if (!local)
		    continue;
		ObjList* o = getRoutes(type);
		if (!o)
		    continue;
		unsigned char sio = getNI(type) | SS7MSU::MTN;
		for (o = o->skipNull(); o; o = o->skipNext()) {
		    const SS7Route* r = static_cast<const SS7Route*>(o->get());
		    if (r->priority())
			continue;
		    // build and send a SLTM to the adjacent node
		    unsigned int len = 4;
		    int sls = l2->sls();
		    SS7Label lbl(type,r->packed(),local,sls);
		    SS7MSU sltm(sio,lbl,0,len+2);
		    unsigned char* d = sltm.getData(lbl.length()+1,len+2);
		    if (!d)
			continue;

		    String addr;
		    addr << SS7PointCode::lookup(type) << "," << lbl;
		    if (debugAt(DebugAll))
			addr << " (" << lbl.opc().pack(type) << ":" << lbl.dpc().pack(type) << ":" << sls << ")";
		    Debug(this,level,"Sending SLTM %s with %u bytes",addr.c_str(),len);

		    *d++ = SS7MsgMTN::SLTM;
		    *d++ = len << 4;
		    unsigned char patt = sls;
		    patt = (patt << 4) | (patt & 0x0f);
		    while (len--)
			*d++ = patt++;
		    if (l2->transmitMSU(sltm))
			dump(sltm,true,sls);
		}
	    }
	}
    }
}

void SS7MTP3::linkChecked(int sls, bool remote)
{
    if (sls < 0)
	return;
    const ObjList* l = &m_links;
    for (; l; l = l->next()) {
	L2Pointer* p = static_cast<L2Pointer*>(l->get());
	if (!p)
	    continue;
	SS7Layer2* l2 = *p;
	if (!l2 || (l2->sls() != sls))
	    continue;
	if (remote) {
	    if (l2->inhibited(SS7Layer2::Unchecked)) {
		// trigger a slightly delayed SLTM check
		u_int64_t t = Time::now() + 100000;
		if ((l2->m_checkTime > t + m_checkT1) || (t - 4000000 > l2->m_checkTime))
		    l2->m_checkTime = t;
	    }
	}
	else {
	    l2->m_checkFail = 0;
	    l2->m_checkTime = m_checkT2 ? Time::now() + m_checkT2 : 0;
	    if (l2->inhibited(SS7Layer2::Unchecked)) {
		Debug(this,DebugNote,"Placing link %d '%s' in service [%p]",
		    sls,l2->toString().c_str(),this);
		l2->inhibit(0,SS7Layer2::Unchecked);
	    }
	}
	break;
    }
}

/* vi: set ts=8 sw=4 sts=4 noet: */
