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yate/libs/ysig/layer2.cpp

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/**
* layer2.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) 2004-2023 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 <string.h>
using namespace TelEngine;
static const TokenDict s_dict_prio[] = {
{ "regular", SS7MSU::Regular },
{ "special", SS7MSU::Special },
{ "circuit", SS7MSU::Circuit },
{ "facility", SS7MSU::Facility },
{ 0, 0 }
};
static const TokenDict s_dict_netind[] = {
{ "international", SS7MSU::International },
{ "spareinternational", SS7MSU::SpareInternational },
{ "national", SS7MSU::National },
{ "reservednational", SS7MSU::ReservedNational },
{ 0, 0 }
};
static const TokenDict s_dict_control[] = {
{ "pause", SS7Layer2::Pause },
{ "resume", SS7Layer2::Resume },
{ "align", SS7Layer2::Align },
{ 0, 0 }
};
SS7MSU::SS7MSU(unsigned char sio, const SS7Label label, void* value, unsigned int len)
{
DataBlock::assign(0,1 + label.length() + len);
unsigned char* d = (unsigned char*)data();
*d++ = sio;
label.store(d);
d += label.length();
if (value && len)
::memcpy(d,value,len);
}
SS7MSU::SS7MSU(unsigned char sif, unsigned char ssf, const SS7Label label, void* value, unsigned int len)
{
DataBlock::assign(0,1 + label.length() + len);
unsigned char* d = (unsigned char*)data();
*d++ = (sif & 0x0f) | (ssf & 0xf0);
label.store(d);
d += label.length();
if (value && len)
::memcpy(d,value,len);
}
SS7MSU::~SS7MSU()
{
}
bool SS7MSU::valid() const
{
// Routing label + data without SIO is between 2 and 272 octets (Q.703 2.3.8)
return (3 <= length()) && (length() <= MAX_TDM_MSU_SIZE);
}
#define CASE_STR(x) case x: return #x
const char* SS7MSU::getServiceName() const
{
switch (getSIF()) {
CASE_STR(SNM);
CASE_STR(MTN);
CASE_STR(MTNS);
CASE_STR(SCCP);
CASE_STR(TUP);
CASE_STR(ISUP);
CASE_STR(DUP_C);
CASE_STR(DUP_F);
CASE_STR(MTP_T);
CASE_STR(BISUP);
CASE_STR(SISUP);
}
return 0;
}
const char* SS7MSU::getPriorityName() const
{
switch (getPrio()) {
CASE_STR(Regular);
CASE_STR(Special);
CASE_STR(Circuit);
CASE_STR(Facility);
}
return 0;
}
const char* SS7MSU::getIndicatorName() const
{
switch (getNI()) {
CASE_STR(International);
CASE_STR(SpareInternational);
CASE_STR(National);
CASE_STR(ReservedNational);
}
return 0;
}
#undef CASE_STR
unsigned char SS7MSU::getPriority(const char* name, unsigned char defVal)
{
return (unsigned char)lookup(name,s_dict_prio,defVal);
}
unsigned char SS7MSU::getNetIndicator(const char* name, unsigned char defVal)
{
return (unsigned char)lookup(name,s_dict_netind,defVal);
}
void SS7Layer2::attach(SS7L2User* l2user)
{
Lock lock(m_l2userMutex);
if (m_l2user == l2user)
return;
SS7L2User* tmp = m_l2user;
m_l2user = l2user;
lock.drop();
if (tmp) {
const char* name = 0;
if (engine() && engine()->find(tmp)) {
name = tmp->toString().safe();
tmp->detach(this);
}
Debug(this,DebugAll,"Detached L2 user (%p,'%s') [%p]",tmp,name,this);
}
if (!l2user)
return;
Debug(this,DebugAll,"Attached L2 user (%p,'%s') [%p]",
l2user,l2user->toString().safe(),this);
insert(l2user);
l2user->attach(this);
}
void SS7Layer2::timerTick(const Time& when)
{
SignallingComponent::timerTick(when);
if (!m_l2userMutex.lock(SignallingEngine::maxLockWait()))
return;
RefPointer<SS7L2User> tmp = m_notify ? m_l2user : 0;
m_notify = false;
m_l2userMutex.unlock();
if (tmp) {
XDebug(this,DebugAll,"SS7Layer2 notifying user [%p]",this);
tmp->notify(this);
}
}
void SS7Layer2::notify()
{
unsigned int wasUp = 0;
bool doNotify = false;
if (!operational()) {
wasUp = upTime();
m_lastUp = 0;
doNotify = (wasUp != 0);
}
else if (!m_lastUp) {
m_lastUp = Time::secNow();
doNotify = true;
}
m_l2userMutex.lock();
m_notify = true;
m_l2userMutex.unlock();
if (doNotify && engine()) {
String text(statusName());
if (wasUp)
text << ", was up " << wasUp;
NamedList params("");
params.addParam("from",toString());
params.addParam("type","ss7-layer2");
params.addParam("operational",String::boolText(operational()));
params.addParam("text",text);
engine()->notify(this,params);
}
}
unsigned int SS7Layer2::status() const
{
return ProcessorOutage;
}
const char* SS7Layer2::statusName(unsigned int status, bool brief) const
{
switch (status) {
case OutOfAlignment:
return brief ? "O" : "Out Of Alignment";
case NormalAlignment:
return brief ? "N" : "Normal Alignment";
case EmergencyAlignment:
return brief ? "E" : "Emergency Alignment";
case OutOfService:
return brief ? "OS" : "Out Of Service";
case ProcessorOutage:
return brief ? "PO" : "Processor Outage";
case Busy:
return brief ? "B" : "Busy";
default:
return brief ? "?" : "Unknown Status";
}
}
bool SS7Layer2::control(Operation oper, NamedList* params)
{
return false;
}
bool SS7Layer2::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;
return TelEngine::controlReturn(&params,(cmd >= 0) && control((Operation)cmd,&params));
}
bool SS7Layer2::getEmergency(NamedList* params, bool emg) const
{
if (m_autoEmergency && !emg) {
const SS7MTP3* mtp3 = YOBJECT(SS7MTP3,m_l2user);
if (mtp3 && !mtp3->linksActive())
emg = true;
}
if (params)
emg = params->getBoolValue(YSTRING("emergency"),emg);
return emg;
}
bool SS7Layer2::inhibit(int setFlags, int clrFlags)
{
int old = m_inhibited;
m_inhibited = (m_inhibited | setFlags) & ~clrFlags;
if (old != m_inhibited || (setFlags & clrFlags)) {
bool cycle = (setFlags & Inactive) && operational();
if (cycle)
control(Pause);
Debug(this,DebugNote,"Link inhibition changed 0x%02X -> 0x%02X [%p]",
old,m_inhibited,this);
if (operational())
notify();
if (cycle)
control(Resume);
}
return true;
}
SS7MTP2::SS7MTP2(const NamedList& params, unsigned int status)
: SignallingComponent(params.safe("SS7MTP2"),&params,"ss7-mtp2"),
SignallingDumpable(SignallingDumper::Mtp2),
Mutex(true,"SS7MTP2"),
m_status(status), m_lStatus(OutOfService), m_rStatus(OutOfAlignment),
m_interval(0), m_resend(0), m_abort(0), m_fillTime(0), m_congestion(false),
m_bsn(127), m_fsn(127), m_bib(true), m_fib(true),
m_lastFsn(128), m_lastBsn(127), m_lastBib(true), m_errors(0), m_maxErrors(64),
m_resendMs(250), m_abortMs(5000), m_fillIntervalMs(20), m_fillLink(true),
m_autostart(false), m_flushMsus(true)
{
#ifdef DEBUG
if (debugAt(DebugAll)) {
String tmp;
params.dump(tmp,"\r\n ",'\'',true);
Debug(this,DebugAll,"SS7MTP2::SS7MTP2(%p,%s) [%p]%s",
&params,statusName(true),this,tmp.c_str());
}
#endif
m_fillLink = params.getBoolValue(YSTRING("filllink"),m_fillLink);
m_maxErrors = params.getIntValue(YSTRING("maxerrors"),64);
if (m_maxErrors < 8)
m_maxErrors = 8;
else if (m_maxErrors > 256)
m_maxErrors = 256;
setDumper(params.getValue(YSTRING("layer2dump")));
}
SS7MTP2::~SS7MTP2()
{
setDumper();
}
unsigned int SS7MTP2::status() const
{
return m_lStatus;
}
void SS7MTP2::setLocalStatus(unsigned int status)
{
if (status == m_lStatus)
return;
DDebug(this,DebugInfo,"Local status change: %s -> %s [%p]",
statusName(m_lStatus,true),statusName(status,true),this);
m_lStatus = status;
m_fillTime = 0;
}
void SS7MTP2::setRemoteStatus(unsigned int status)
{
if (status == m_rStatus)
return;
DDebug(this,DebugInfo,"Remote status change: %s -> %s [%p]",
statusName(m_rStatus,true),statusName(status,true),this);
m_rStatus = status;
}
bool SS7MTP2::aligned() const
{
return ((m_lStatus == NormalAlignment) || (m_lStatus == EmergencyAlignment)) &&
((m_rStatus == NormalAlignment) || (m_rStatus == EmergencyAlignment));
}
bool SS7MTP2::operational() const
{
return aligned() && !m_interval;
}
bool SS7MTP2::initialize(const NamedList* config)
{
#ifdef DEBUG
String tmp;
if (config && debugAt(DebugAll))
config->dump(tmp,"\r\n ",'\'',true);
Debug(this,DebugInfo,"SS7MTP2::initialize(%p) [%p]%s",config,this,tmp.c_str());
#endif
if (config) {
debugLevel(config->getIntValue(YSTRING("debuglevel_mtp2"),
config->getIntValue(YSTRING("debuglevel"),-1)));
m_autoEmergency = config->getBoolValue(YSTRING("autoemergency"),true);
unsigned int maxErrors = config->getIntValue(YSTRING("maxerrors"),m_maxErrors);
if (maxErrors < 8)
m_maxErrors = 8;
else if (maxErrors > 256)
m_maxErrors = 256;
else
m_maxErrors = maxErrors;
}
m_autostart = !config || config->getBoolValue(YSTRING("autostart"),true);
m_flushMsus = !config || config->getBoolValue(YSTRING("flushmsus"),true);
if (config && !iface()) {
NamedList params("");
if (resolveConfig(YSTRING("sig"),params,config) ||
resolveConfig(YSTRING("basename"),params,config)) {
params.addParam("basename",params);
params.addParam("protocol","ss7");
int rx = params.getIntValue(YSTRING("rxunderrun"));
if ((rx > 0) && (rx < 25))
params.setParam("rxunderrun","25");
SignallingInterface* ifc = YSIGCREATE(SignallingInterface,&params);
if (!ifc)
return false;
SignallingReceiver::attach(ifc);
if (!(ifc->initialize(&params) && control((Operation)SignallingInterface::Enable,&params)))
TelEngine::destruct(SignallingReceiver::attach(0));
}
}
return iface() && control(Resume,const_cast<NamedList*>(config));
}
bool SS7MTP2::control(Operation oper, NamedList* params)
{
if (params) {
lock();
m_fillLink = params->getBoolValue(YSTRING("filllink"),m_fillLink);
m_autoEmergency = params->getBoolValue(YSTRING("autoemergency"),m_autoEmergency);
m_autostart = params->getBoolValue(YSTRING("autostart"),m_autostart);
m_flushMsus = params->getBoolValue(YSTRING("flushmsus"),m_flushMsus);
unsigned int maxErrors = params->getIntValue(YSTRING("maxerrors"),m_maxErrors);
if (maxErrors < 8)
m_maxErrors = 8;
else if (maxErrors > 256)
m_maxErrors = 256;
else
m_maxErrors = maxErrors;
// The following are for test purposes
if (params->getBoolValue(YSTRING("toggle-bib")))
m_bib = !m_bib;
if (params->getBoolValue(YSTRING("toggle-fib")))
m_fib = !m_fib;
int tmp = params->getIntValue(YSTRING("change-fsn"));
if (tmp)
m_fsn = (m_fsn + tmp) & 0x7f;
unlock();
tmp = params->getIntValue(YSTRING("send-lssu"),-1);
if (tmp >= 0)
transmitLSSU(tmp);
if (params->getBoolValue(YSTRING("send-fisu")))
transmitFISU();
if (params->getBoolValue(YSTRING("simulate-error")))
notify(SignallingInterface::HardwareError);
}
switch (oper) {
case Pause:
abortAlignment(false);
return TelEngine::controlReturn(params,true);
case Resume:
if (aligned() || !m_autostart)
return TelEngine::controlReturn(params,true);
// fall-through
case Align:
startAlignment(getEmergency(params));
return TelEngine::controlReturn(params,true);
case Status:
return TelEngine::controlReturn(params,operational());
default:
return SignallingReceiver::control((SignallingInterface::Operation)oper,params);
}
}
bool SS7MTP2::notify(SignallingInterface::Notification event)
{
switch (event) {
case SignallingInterface::LinkDown:
Debug(this,DebugWarn,"Interface is down - realigning [%p]",this);
abortAlignment(m_autostart);
break;
case SignallingInterface::LinkUp:
Debug(this,DebugInfo,"Interface is up [%p]",this);
control(Resume);
break;
default:
XDebug(this,DebugMild,"Got error %u: %s [%p]",
event,lookup(event,SignallingInterface::s_notifName),this);
{
unsigned int err = (m_errors += 256) >> 8;
if (err >= (operational() ? m_maxErrors :
((m_rStatus == EmergencyAlignment) ? 1 : 4))) {
Debug(this,DebugWarn,"Got %u errors - realigning [%p]",err,this);
abortAlignment(m_autostart);
}
}
}
return true;
}
void SS7MTP2::timerTick(const Time& when)
{
SS7Layer2::timerTick(when);
if (!lock(SignallingEngine::maxLockWait()))
return;
bool tout = m_interval && (when >= m_interval);
if (tout)
m_interval = 0;
bool aborting = m_abort && (when >= m_abort);
if (aborting)
m_abort = m_resend = 0;
bool resend = m_resend && (when >= m_resend);
if (resend)
m_resend = 0;
unlock();
if (aborting) {
Debug(this,DebugWarn,"Timeout for MSU acknowledgement, realigning [%p]",this);
abortAlignment(m_autostart);
return;
}
if (operational()) {
if (tout) {
Debug(this,DebugInfo,"Proving period ended, link operational [%p]",this);
lock();
m_lastSeqRx = -1;
unsigned int q = m_queue.count();
if (!q)
;
else if (m_flushMsus || q >= 64) {
// there shouldn't have been that many queued MSUs
Debug(this,DebugWarn,"Cleaning %u queued MSUs from proved link! [%p]",q,this);
m_queue.clear();
}
else {
Debug(this,DebugNote,"Changing FSN of %u MSUs queued in proved link! [%p]",q,this);
// transmit a FISU just before the bunch of MSUs
transmitFISU();
resend = true;
// reset the FSN of packets still waiting in queue
m_lastBsn = m_fsn;
ObjList* l = m_queue.skipNull();
for (; l; l = l->skipNext()) {
DataBlock* packet = static_cast<DataBlock*>(l->get());
unsigned char* buf = (unsigned char*)packet->data();
// update the FSN/FIB in packet, BSN/BIB will be updated later
m_fsn = (m_fsn + 1) & 0x7f;
buf[1] = m_fib ? m_fsn | 0x80 : m_fsn;
}
Debug(this,DebugNote,"Renumbered %u packets, last FSN=%u [%p]",
q,m_fsn,this);
}
unlock();
SS7Layer2::notify();
}
if (resend) {
int c = 0;
lock();
m_fib = m_lastBib;
ObjList* l = m_queue.skipNull();
for (; l; l = l->skipNext()) {
DataBlock* packet = static_cast<DataBlock*>(l->get());
unsigned char* buf = (unsigned char*)packet->data();
// update the BSN/BIB in packet
buf[0] = m_bib ? m_bsn | 0x80 : m_bsn;
// also adjust the FIB but not FSN
if (m_fib)
buf[1] |= 0x80;
else
buf[1] &= 0x7f;
Debug(this,DebugInfo,"Resending packet %p with FSN=%u [%p]",
packet,buf[1] & 0x7f,this);
txPacket(*packet,false,SignallingInterface::SS7Msu);
c++;
}
if (c) {
m_resend = Time::now() + (1000 * m_resendMs);
m_fillTime = 0;
Debug(this,DebugInfo,"Resent %d packets, last bsn=%u/%u [%p]",
c,m_lastBsn,m_lastBib,this);
}
unlock();
}
}
else if (tout) {
switch (m_lStatus) {
case OutOfService:
if (m_status != OutOfService)
setLocalStatus(OutOfAlignment);
break;
case OutOfAlignment:
Debug(this,DebugMild,"Initial alignment timed out, retrying");
break;
}
}
if (when >= m_fillTime) {
if (operational())
transmitFISU();
else
transmitLSSU();
}
}
// Transmit a MSU retaining a copy for retransmissions
bool SS7MTP2::transmitMSU(const SS7MSU& msu)
{
if (msu.length() < 3) {
Debug(this,DebugWarn,"Asked to send too short MSU of length %u [%p]",
msu.length(),this);
return false;
}
if (!operational()) {
DDebug(this,DebugInfo,"Asked to send MSU while not operational [%p]",this);
return false;
}
#ifdef XDEBUG
String tmp;
tmp.hexify((void*)msu.data(),msu.length(),' ');
XDebug(this,DebugAll,"SS7MTP2::transmitMSU(%p) len=%u: %s [%p]",
&msu,msu.length(),tmp.c_str(),this);
#endif
// if we don't have an attached interface don't bother
if (!iface())
return false;
DataBlock* packet = new DataBlock(0,3);
*packet += msu;
// set BSN+BIB, FSN+FIB, LENGTH in the 3 extra bytes
unsigned char* buf = (unsigned char*)packet->data();
buf[2] = (msu.length() > 0x3f) ? 0x3f : msu.length() & 0x3f;
// lock the object so we can safely use member variables
Lock lock(this);
m_fsn = (m_fsn + 1) & 0x7f;
m_fillTime = 0;
buf[0] = m_bib ? m_bsn | 0x80 : m_bsn;
buf[1] = m_fib ? m_fsn | 0x80 : m_fsn;
DDebug(this,DebugInfo,"New local bsn=%u/%d fsn=%u/%d [%p]",
m_bsn,m_bib,m_fsn,m_fib,this);
m_queue.append(packet);
DDebug(this,DebugInfo,"There are %u packets in queue [%p]",
m_queue.count(),this);
bool ok = false;
if (operational()) {
ok = txPacket(*packet,false,SignallingInterface::SS7Msu);
transmitFISU();
}
if (!m_abort)
m_abort = Time::now() + (1000 * m_abortMs);
if (!m_resend)
m_resend = Time::now() + (1000 * m_resendMs);
return ok;
}
// Remove the MSUs in the queue, the upper layer will move them to another link
void SS7MTP2::recoverMSU(int sequence)
{
Debug(this,DebugInfo,"Recovering MSUs from sequence %d",sequence);
for (;;) {
lock();
DataBlock* pkt = static_cast<DataBlock*>(m_queue.remove(false));
unlock();
if (!pkt)
break;
unsigned char* head = pkt->data(0,4);
if (head) {
int seq = head[1] & 0x7f;
if (sequence < 0 || ((seq - sequence) & 0x7f) < 0x3f) {
sequence = -1;
SS7MSU msu(head + 3,pkt->length() - 3);
recoveredMSU(msu);
}
else
Debug(this,DebugAll,"Not recovering MSU with seq=%d, requested %d",
seq,sequence);
}
TelEngine::destruct(pkt);
}
}
// Decode a received packet into signalling units
bool SS7MTP2::receivedPacket(const DataBlock& packet)
{
dump(packet,false,sls());
if (packet.length() < 3) {
XDebug(this,DebugMild,"Received short packet of length %u [%p]",
packet.length(),this);
return false;
}
const unsigned char* buf = (const unsigned char*)packet.data();
unsigned int len = buf[2] & 0x3f;
if ((len == 0x3f) && (packet.length() > 0x42))
len = packet.length() - 3;
else if (len != (packet.length() - 3)) {
XDebug(this,DebugMild,"Received packet with length indicator %u but length %u [%p]",
len,packet.length(),this);
return false;
}
// adjust error counter
if (m_errors && operational())
m_errors--;
// process LSSU and FISU to detect link status changes
switch (len) {
case 2:
processLSSU(buf[3] + (buf[4] << 8));
break;
case 1:
processLSSU(buf[3]);
break;
case 0:
processFISU();
break;
}
// check sequence numbers
unsigned char bsn = buf[0] & 0x7f;
unsigned char fsn = buf[1] & 0x7f;
bool bib = (buf[0] & 0x80) != 0;
bool fib = (buf[1] & 0x80) != 0;
// lock the object as we modify members
lock();
// sequence control as explained by Q.703 5.2.2
unsigned char diff = (fsn - m_bsn) & 0x7f;
XDebug(this,DebugAll,"got bsn=%u/%d fsn=%u/%d local bsn=%u/%d fsn=%u/%d diff=%u len=%u [%p]",
bsn,bib,fsn,fib,m_bsn,m_bib,m_fsn,m_fib,diff,len,this);
if (aligned()) {
// received FSN should be only 1 ahead of last we handled
if (diff > 1) {
if (diff < 64)
Debug(this,DebugMild,"We lost %u packets, remote fsn=%u local bsn=%u [%p]",
(diff - 1),fsn,m_bsn,this);
if (fsn != m_lastFsn) {
m_lastFsn = fsn;
// toggle BIB to request immediate retransmission
m_bib = !m_bib;
DDebug(this,DebugInfo,"New local bsn=%u/%d fsn=%u/%d [%p]",
m_bsn,m_bib,m_fsn,m_fib,this);
}
}
else
m_lastFsn = 128;
if (m_lastBib != bib) {
Debug(this,DebugNote,"Remote requested resend remote bsn=%u local fsn=%u [%p]",
bsn,m_fsn,this);
m_lastBib = bib;
m_resend = Time::now();
}
unqueueAck(bsn);
// end proving now if received MSU with correct sequence
if (m_interval && (diff == 1))
m_interval = Time::now();
}
else {
// keep sequence numbers in sync with the remote
m_bsn = fsn;
m_bib = fib;
m_lastBsn = bsn;
m_lastBib = bib;
m_fillTime = 0;
}
unlock();
if (len < 3)
return true;
// just drop MSUs if not operational or out of sequence
if (!((diff == 1) && operational()))
return false;
m_lastSeqRx = m_bsn = fsn;
m_fillTime = 0;
DDebug(this,DebugInfo,"New local bsn=%u/%d fsn=%u/%d [%p]",
m_bsn,m_bib,m_fsn,m_fib,this);
SS7MSU msu((void*)(buf+3),len,false);
bool ok = receivedMSU(msu);
if (!ok) {
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());
}
msu.clear(false);
return ok;
}
// Remove from send queue confirmed packets up to received BSN
void SS7MTP2::unqueueAck(unsigned char bsn)
{
if (m_lastBsn == bsn)
return;
// positive acknowledgement - Q.703 6.3.1
DDebug(this,DebugNote,"Unqueueing packets in range %u - %u [%p]",
m_lastBsn,bsn,this);
int c = 0;
for (;;) {
unsigned char efsn = (m_lastBsn + 1) & 0x7f;
DataBlock* packet = static_cast<DataBlock*>(m_queue.get());
if (!packet) {
Debug(this,DebugMild,"Queue empty while expecting packet with FSN=%u [%p]",
efsn,this);
m_lastBsn = bsn;
// all packets confirmed - stop resending
m_resend = 0;
m_abort = 0;
break;
}
unsigned char pfsn = ((const unsigned char*)packet->data())[1] & 0x7f;
if (pfsn != efsn)
Debug(this,DebugMild,"Found in queue packet with FSN=%u expected %u [%p]",
pfsn,efsn,this);
c++;
XDebug(this,DebugInfo,"Unqueueing packet %p with FSN=%u [%p]",
packet,pfsn,this);
m_queue.remove(packet);
m_lastBsn = pfsn;
if (pfsn == bsn) {
if (m_queue.count() == 0) {
// all packets confirmed - stop resending
m_resend = 0;
m_abort = 0;
}
break;
}
}
if (c) {
DDebug(this,DebugNote,"Unqueued %d packets up to FSN=%u [%p]",c,bsn,this);
m_abort = m_resend ? Time::now() + (1000 * m_abortMs) : 0;
}
}
// Transmit packet to interface, dump it if successfull
bool SS7MTP2::txPacket(const DataBlock& packet, bool repeat, SignallingInterface::PacketType type)
{
if (transmitPacket(packet,repeat,type)) {
dump(packet,true,sls());
return true;
}
return false;
}
// Process incoming FISU
void SS7MTP2::processFISU()
{
if (m_fillLink && !aligned())
m_fillTime = 0;
}
// Process incoming LSSU
void SS7MTP2::processLSSU(unsigned int status)
{
status &= 0x07;
XDebug(this,DebugAll,"Process LSSU with status %s (L:%s R:%s)",
statusName(status,true),statusName(m_lStatus,true),statusName(m_rStatus,true));
bool unaligned = !aligned();
setRemoteStatus(status);
if (status == Busy) {
if (unaligned)
abortAlignment(m_autostart);
else
m_congestion = true;
return;
}
// cancel any timer except aborted or initial alignment
switch (status) {
case OutOfAlignment:
case NormalAlignment:
case EmergencyAlignment:
if (m_lStatus == OutOfService) {
if (m_status != OutOfService)
setLocalStatus(OutOfAlignment);
break;
}
if (!(unaligned && startProving()))
setLocalStatus(m_status);
break;
default:
if (!m_interval) {
if (m_status != OutOfService)
abortAlignment(m_autostart);
}
else if (m_lStatus != OutOfService && m_lStatus != OutOfAlignment)
m_interval = 0;
}
}
// Emit a locally generated LSSU
bool SS7MTP2::transmitLSSU(unsigned int status)
{
unsigned char buf[5];
buf[2] = 1;
buf[3] = status & 0xff;
status = (status >> 8) & 0xff;
if (status) {
// we need 2-byte LSSU to fit
buf[2] = 2;
buf[4] = status;
}
// lock the object so we can safely use member variables
lock();
bool repeat = m_fillLink && (m_status != OutOfService);
buf[0] = m_bib ? m_bsn | 0x80 : m_bsn;
buf[1] = m_fib ? m_fsn | 0x80 : m_fsn;
DataBlock packet(buf,buf[2]+3,false);
XDebug(this,DebugAll,"Transmit LSSU with status %s",statusName(buf[3],true));
bool ok = txPacket(packet,repeat,SignallingInterface::SS7Lssu);
m_fillTime = Time::now() + (1000 * m_fillIntervalMs);
unlock();
packet.clear(false);
return ok;
}
// Emit a locally generated FISU
bool SS7MTP2::transmitFISU()
{
unsigned char buf[3];
buf[2] = 0;
// lock the object so we can safely use member variables
lock();
buf[0] = m_bib ? m_bsn | 0x80 : m_bsn;
buf[1] = m_fib ? m_fsn | 0x80 : m_fsn;
DataBlock packet(buf,3,false);
bool ok = txPacket(packet,m_fillLink,SignallingInterface::SS7Fisu);
m_fillTime = Time::now() + (1000 * m_fillIntervalMs);
unlock();
packet.clear(false);
return ok;
}
void SS7MTP2::startAlignment(bool emergency)
{
lock();
unsigned int q = m_queue.count();
if (q)
Debug(this,DebugWarn,"Starting alignment with %u queued MSUs! [%p]",q,this);
else
Debug(this,DebugInfo,"Starting %s alignment [%p]",
(emergency ? "emergency" : "normal"),this);
m_bsn = m_fsn = 127;
m_bib = m_fib = true;
if (m_lStatus != OutOfService) {
setLocalStatus(OutOfService);
unlock();
transmitLSSU();
lock();
}
m_status = emergency ? EmergencyAlignment : NormalAlignment;
m_abort = m_resend = 0;
setLocalStatus(OutOfAlignment);
m_interval = Time::now() + 5000000;
unlock();
transmitLSSU();
SS7Layer2::notify();
}
void SS7MTP2::abortAlignment(bool retry)
{
lock();
DDebug(this,DebugNote,"Aborting alignment [%p]",this);
if (!retry)
m_status = OutOfService;
setLocalStatus(OutOfService);
m_interval = Time::now() + 1000000;
m_abort = m_resend = 0;
m_errors = 0;
m_bsn = m_fsn = 127;
m_bib = m_fib = true;
m_fillTime = 0;
unlock();
transmitLSSU();
SS7Layer2::notify();
}
bool SS7MTP2::startProving()
{
if (!aligned())
return false;
lock();
bool emg = (m_rStatus == EmergencyAlignment);
Debug(this,DebugInfo,"Starting %s proving interval [%p]",
emg ? "emergency" : "normal",this);
// proving interval is defined in octet transmission times
u_int64_t interval = emg ? 4096 : 65536;
// FIXME: assuming 64 kbit/s, 125 usec/octet
m_interval = Time::now() + (125 * interval);
unlock();
return true;
}
/* vi: set ts=8 sw=4 sts=4 noet: */
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