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/**@file GSM/SIP Call Control -- GSM 04.08, ISDN ITU-T Q.931, SIP IETF RFC-3261, RTP IETF RFC-3550. */
/*
* Copyright 2008, 2009 Free Software Foundation, Inc.
*
* This software is distributed under the terms of the GNU Public License.
* See the COPYING file in the main directory for details.
*
* This use of this software may be subject to additional restrictions.
* See the LEGAL file in the main directory for details.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
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. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
Abbreviations:
MTC -- Mobile Terminated Connect (someone calling the mobile)
MOC -- Mobile Originated Connect (mobile calling out)
MTD -- Mobile Terminated Disconnect (other party hangs up)
MOD -- Mobile Originated Disconnect (mobile hangs up)
E-MOC -- Emergency Mobile Originated Connect (mobile calling out)
*/
#include <Globals.h>
#include "ControlCommon.h"
#include <GSMLogicalChannel.h>
#include <GSML3RRMessages.h>
#include <GSML3MMMessages.h>
#include <GSML3CCMessages.h>
#include <GSMConfig.h>
#include <SIPInterface.h>
#include <SIPUtility.h>
#include <SIPMessage.h>
#include <SIPEngine.h>
#include <Logger.h>
using namespace std;
using namespace GSM;
using namespace Control;
using namespace SIP;
/**
Return an even UDP port number for the RTP even/odd pair.
*/
unsigned allocateRTPPorts()
{
// FIXME -- We need a real port allocator.
const unsigned base = gConfig.getNum("RTP.Start");
const unsigned range = gConfig.getNum("RTP.Range");
const unsigned top = base+range;
static Mutex lock;
// Pick a random starting point.
static unsigned port = base + 2*(random()%(range/2));
lock.lock();
unsigned retVal = port;
port += 2;
if (port>=top) port=base;
lock.unlock();
return retVal;
}
/**
Force clearing on the GSM side.
@param transaction The call transaction record.
@param LCH The logical channel.
@param cause The L3 abort cause.
*/
void forceGSMClearing(TransactionEntry& transaction, LogicalChannel *LCH, const L3Cause& cause)
{
if (transaction.Q931State()==TransactionEntry::NullState) return;
LOG(INFO) << "Q.931 state " << transaction.Q931State();
if (!transaction.clearing()) {
LCH->send(L3Disconnect(1-transaction.TIFlag(),transaction.TIValue(),cause));
}
LCH->send(L3ReleaseComplete(1-transaction.TIFlag(),transaction.TIValue()));
LCH->send(L3ChannelRelease());
transaction.resetTimers();
transaction.Q931State(TransactionEntry::NullState);
LCH->send(RELEASE);
gTransactionTable.update(transaction);
}
/**
Force clearing on the SIP side.
@param transaction The call transaction record.
*/
void forceSIPClearing(TransactionEntry& transaction)
{
if (transaction.SIP().state()==SIP::Cleared) return;
LOG(INFO) << "SIP state " << transaction.SIP().state();
if (transaction.SIP().state()!=SIP::Clearing) {
// This also changes the SIP state to "clearing".
transaction.SIP().MODSendBYE();
} else {
transaction.SIP().MODResendBYE();
}
// FIXME -- We need to loop here and wait for the OK or timeout from the SIP side.
gTransactionTable.update(transaction);
}
/**
Abort the call. Does not clear the transaction history.
@param transaction The call transaction record.
@param LCH The logical channel.
@param cause The L3 abort cause.
*/
void abortCall(TransactionEntry& transaction, LogicalChannel *LCH, const L3Cause& cause)
{
LOG(INFO) << "cause: " << cause << ", transction: " << transaction;
forceGSMClearing(transaction,LCH,cause);
forceSIPClearing(transaction);
clearTransactionHistory(transaction);
}
/**
Allocate a TCH and clean up any failure.
@param SDCCH The SDCCH that will be used to send the assignment.
@return A pointer to the TCH or NULL on failure.
*/
TCHFACCHLogicalChannel *allocateTCH(SDCCHLogicalChannel *SDCCH)
{
TCHFACCHLogicalChannel *TCH = gBTS.getTCH();
if (!TCH) {
LOG(NOTICE) << "CONGESTION, no TCH available for assignment";
// Cause 0x16 is "congestion".
SDCCH->send(L3CMServiceReject(0x16));
SDCCH->send(L3ChannelRelease());
}
return TCH;
}
/**
Assign a full rate traffic channel and clean up any failures.
@param SDCCH The SDCCH on which to send the assignment.
@param TCH The TCH to be assigned.
@bool True on successful transfer.
*/
bool assignTCHF(TransactionEntry& transaction, SDCCHLogicalChannel *SDCCH, TCHFACCHLogicalChannel *TCH)
{
TCH->open();
TCH->setPhy(*SDCCH);
// Send the assignment.
LOG(INFO) << "assignTCHF sending AssignmentCommand for " << TCH << " on " << SDCCH;
SDCCH->send(L3AssignmentCommand(TCH->channelDescription(),L3ChannelMode(L3ChannelMode::SpeechV1)));
// This read is SUPPOSED to time out if the assignment was successful.
// Pad the timeout just in case there's a large latency somewhere.
L3Frame *result = SDCCH->recv(T3107ms+2000);
if (result==NULL) {
LOG(INFO) << "assignmentTCHF exiting normally";
SDCCH->send(RELEASE);
return true;
}
// If we got here, the assignment failed.
LOG(NOTICE) << "assignTCHF received " << *result;
delete result;
// Turn off the TCH.
TCH->send(RELEASE);
// Shut down the SIP side of the call.
forceSIPClearing(transaction);
// RR Cause 0x04 -- "abnormal release, no activity on the radio path"
SDCCH->send(L3ChannelRelease(0x04));
// Clean up the transaction table.
clearTransactionHistory(transaction);
// Indicate failure.
return false;
}
/**
Process a message received from the phone during a call.
This function processes all deviations from the "call connected" state.
For now, we handle call clearing and politely reject everything else.
@param transaction The transaction record for this call.
@param LCH The logical channel for the transaction.
@param message A pointer to the receiver message.
@return true If the call has been cleared and the channel released.
*/
bool callManagementDispatchGSM(TransactionEntry& transaction, LogicalChannel* LCH, const L3Message *message)
{
LOG(DEBUG) << "from " << transaction.subscriber() << " message " << *message;
// FIXME -- This dispatch section should be something more efficient with PD and MTI swtiches.
// Actually check state before taking action.
//if (transaction.SIP().state()==SIP::Cleared) return true;
//if (transaction.Q931State()==TransactionEntry::NullState) return true;
// Call connection steps.
// Connect Acknowledge
if (dynamic_cast<const L3ConnectAcknowledge*>(message)) {
LOG(INFO) << "GSM Connect Acknowledge " << transaction.subscriber();
transaction.resetTimers();
transaction.Q931State(TransactionEntry::Active);
gTransactionTable.update(transaction);
return false;
}
// Connect
// GSM 04.08 5.2.2.5 and 5.2.2.6
if (dynamic_cast<const L3Connect*>(message)) {
LOG(INFO) << "GSM Connect " << transaction.subscriber();
transaction.resetTimers();
transaction.Q931State(TransactionEntry::Active);
gTransactionTable.update(transaction);
return false;
}
// Call Confirmed
// GSM 04.08 5.2.2.3.2
// "Call Confirmed" is the GSM MTC counterpart to "Call Proceeding"
if (dynamic_cast<const L3CallConfirmed*>(message)) {
LOG(INFO) << "GSM Call Confirmed " << transaction.subscriber();
transaction.T303().reset();
transaction.T310().set();
transaction.Q931State(TransactionEntry::MTCConfirmed);
gTransactionTable.update(transaction);
return false;
}
// Alerting
// GSM 04.08 5.2.2.3.2
if (dynamic_cast<const L3Alerting*>(message)) {
LOG(INFO) << "GSM Alerting " << transaction.subscriber();
transaction.T310().reset();
transaction.T301().set();
transaction.Q931State(TransactionEntry::CallReceived);
gTransactionTable.update(transaction);
return false;
}
// Call clearing steps.
// Good diagrams in GSM 04.08 7.3.4
// FIXME -- We should be checking TI values against the transaction object.
// Disconnect (1st step of MOD)
// GSM 04.08 5.4.3.2
if (const L3Disconnect* disconnect = dynamic_cast<const L3Disconnect*>(message)) {
LOG(INFO) << "GSM Disconnect " << transaction.subscriber();
transaction.resetTimers();
LCH->send(L3Release(1-transaction.TIFlag(),transaction.TIValue()));
transaction.T308().set();
transaction.Q931State(TransactionEntry::ReleaseRequest);
transaction.SIP().MODSendBYE();
gTransactionTable.update(transaction);
return false;
}
// Release (2nd step of MTD)
if (const L3Release* release = dynamic_cast<const L3Release*>(message)) {
LOG(INFO) << "GSM Release " << transaction.subscriber();
transaction.resetTimers();
LCH->send(L3ReleaseComplete(1-transaction.TIFlag(),transaction.TIValue()));
LCH->send(L3ChannelRelease());
transaction.Q931State(TransactionEntry::NullState);
transaction.SIP().MTDSendOK();
gTransactionTable.update(transaction);
return true;
}
// Release Complete (3nd step of MOD)
// GSM 04.08 5.4.3.4
if (dynamic_cast<const L3ReleaseComplete*>(message)) {
LOG(INFO) << "GSM Release Complete " << transaction.subscriber();
transaction.resetTimers();
LCH->send(L3ChannelRelease());
transaction.Q931State(TransactionEntry::NullState);
forceSIPClearing(transaction);
clearTransactionHistory(transaction);
return true;
}
// IMSI Detach -- the phone is shutting off.
if (const L3IMSIDetachIndication* detach = dynamic_cast<const L3IMSIDetachIndication*>(message)) {
// The IMSI detach procedure will release the LCH.
LOG(INFO) << "GSM IMSI Detach " << transaction.subscriber();
IMSIDetachController(detach,LCH);
forceSIPClearing(transaction);
clearTransactionHistory(transaction);
return true;
}
// Start DTMF
// Send a SIP INFO to generate a tone in Asterisk.
if (const L3StartDTMF* keypress = dynamic_cast<const L3StartDTMF*>(message)) {
unsigned keyVal = encodeBCDChar(keypress->key().IA5());
LOG(INFO) << "DMTF key=" << keyVal << ' ' << transaction.subscriber();
bool success = transaction.SIP().sendINFOAndWaitForOK(keyVal);
// Cause 0x3f means "service or option not available".
if (success) LCH->send(L3StartDTMFAcknowledge(1-transaction.TIFlag(),transaction.TIValue(),keypress->key()));
else LCH->send(L3StartDTMFReject(1-transaction.TIFlag(),transaction.TIValue(),0x3f));
return false;
}
// Stop DTMF
// Since we use SIP INFO we just ack.
if (const L3StopDTMF* stop = dynamic_cast<const L3StopDTMF*>(message)) {
LCH->send(L3StopDTMFAcknowledge(1-transaction.TIFlag(),transaction.TIValue()));
return false;
}
// Stubs for unsupported features.
// We need to answer the handset so it doesn't hang.
// CM Service Request
// This is the gateway to a much more complex state machine.
// For now, we're cutting it off right here.
if (dynamic_cast<const L3CMServiceRequest*>(message)) {
LOG(NOTICE) << "cannot accept additional CM Service Request from " << transaction.subscriber();
// Cause 0x20 means "serivce not supported".
LCH->send(L3CMServiceReject(0x20));
return false;
}
// Hold
if (const L3Hold* hold = dynamic_cast<const L3Hold*>(message)) {
LOG(NOTICE) << "rejecting hold request from " << transaction.subscriber();
// Default cause is 0x3f, option not available
LCH->send(L3HoldReject(1-transaction.TIFlag(),transaction.TIValue()));
return false;
}
if (message) LOG(NOTICE) << "no support for message " << *message << " from " << transaction.subscriber();
else LOG(NOTICE) << "no support for unrecognized message from " << transaction.subscriber();
// If we got here, we're ignoring the message.
return false;
}
/**
Update vocoder data transfers in both directions.
@param transaction The transaction object for this call.
@param TCH The traffic channel for this call.
@return True if anything was transferred.
*/
bool updateCallTraffic(TransactionEntry &transaction, TCHFACCHLogicalChannel *TCH)
{
bool activity = false;
SIPEngine& engine = transaction.SIP();
// Transfer in the downlink direction (RTP->GSM).
// Blocking call. On average returns 1 time per 20 ms.
// Returns non-zero if anything really happened.
// Make the rxFrame buffer big enough for G.711.
unsigned char rxFrame[160];
if (engine.RxFrame(rxFrame)) {
activity = true;
TCH->sendTCH(rxFrame);
}
// Transfer in the uplink direction (GSM->RTP).
// Flush FIFO to limit latency.
while (TCH->queueSize()>2) delete[] TCH->recvTCH();
if (unsigned char *txFrame = TCH->recvTCH()) {
activity = true;
// Send on RTP.
engine.TxFrame(txFrame);
delete[] txFrame;
}
// Return a flag so the caller will know if anything transferred.
return activity;
}
/**
Check GSM signalling.
Can block for up to 52 GSM L1 frames (240 ms) because LCH::send is blocking.
@param transaction The call's TransactionEntry.
@param LCH The call's logical channel (TCH/FACCH or SDCCH).
@return true If the call was cleared.
*/
bool updateGSMSignalling(TransactionEntry &transaction, LogicalChannel *LCH, unsigned timeout=0)
{
if (transaction.Q931State()==TransactionEntry::NullState) return true;
// Any Q.931 timer expired?
if (transaction.timerExpired()) {
// Cause 0x66, "recover on timer expiry"
abortCall(transaction,LCH,L3Cause(0x66));
return true;
}
// Look for a control message from MS side.
if (L3Frame *l3 = LCH->recv(timeout)) {
// Check for lower-layer error.
if (l3->primitive() == ERROR) return true;
// Parse and dispatch.
L3Message *l3msg = parseL3(*l3);
delete l3;
bool cleared = false;
if (l3msg) {
LOG(DEBUG) << "received " << *l3msg;
cleared = callManagementDispatchGSM(transaction, LCH, l3msg);
delete l3msg;
}
return cleared;
}
// If we are here, we have timed out, but assume the call is still running.
return false;
}
/**
Check SIP and GSM signalling.
Can block for up to 52 GSM L1 frames (240 ms) because LCH::send is blocking.
@param transaction The call's TransactionEntry.
@param LCH The call's logical channel (TCH/FACCH or SDCCH).
@return true If the call is cleared in both domains.
*/
bool updateSignalling(TransactionEntry &transaction, LogicalChannel *LCH, unsigned timeout=0)
{
bool GSMCleared = (updateGSMSignalling(transaction,LCH,timeout));
// Look for a SIP message.
SIPEngine& engine = transaction.SIP();
if (engine.MTDCheckBYE() == SIP::Clearing) {
if (!transaction.clearing()) {
LOG(DEBUG) << "got BYE";
LCH->send(L3Disconnect(1-transaction.TIFlag(),transaction.TIValue()));
transaction.T305().set();
transaction.Q931State(TransactionEntry::DisconnectIndication);
// Return false, because it the call is not yet cleared.
return false;
} else {
// If we're already clearing, send BYE again.
//engine.MODSendBYE();
}
}
bool SIPCleared = (engine.state()==SIP::Cleared);
return GSMCleared && SIPCleared;
}
/**
Poll for activity while in a call.
Sleep if needed to prevent fast spinning.
Will block for up to 250 ms.
@param transaction The call's TransactionEntry.
@param TCH The call's TCH+FACCH.
@return true If the call was cleared.
*/
bool pollInCall(TransactionEntry &transaction, TCHFACCHLogicalChannel *TCH)
{
// See if the radio link disappeared.
if (TCH->radioFailure()) {
LOG(NOTICE) << "radio link failure, dropped call";
forceSIPClearing(transaction);
clearTransactionHistory(transaction);
return true;
}
// Process pending SIP and GSM signalling.
// If this returns true, it means the call is fully cleared.
if (updateSignalling(transaction,TCH)) return true;
// Transfer vocoder data.
// If anything happened, then the call is still up.
if (updateCallTraffic(transaction,TCH)) return false;
// If nothing happened, sleep so we don't burn up the CPU cycles.
msleep(250);
return false;
}
/**
Pause for a given time while managing the connection.
Returns on timeout or call clearing.
Used for debugging to simulate ringing at terminating end.
@param transaction The transaction record for the call.
@param TCH The TCH+FACCH sed for this call.
@param waitTime_ms The maximum time to wait, in ms.
@return true If the call is cleared during the wait.
*/
bool waitInCall(TransactionEntry& transaction, TCHFACCHLogicalChannel *TCH, unsigned waitTime_ms)
{
Timeval targetTime(waitTime_ms);
LOG(DEBUG);
while (!targetTime.passed()) {
if (pollInCall(transaction,TCH)) return true;
}
return false;
}
/**
This is the standard call manangement loop, regardless of the origination type.
This function returns when the call is cleared and the channel is released.
@param transaction The transaction record for this call, will be cleared on exit.
@param TCH The TCH+FACCH for the call.
*/
void callManagementLoop(TransactionEntry &transaction, TCHFACCHLogicalChannel* TCH)
{
LOG(INFO) << "MOC MTC connected, " << transaction.subscriber() << " entering callManagementLoop";
transaction.SIP().FlushRTP();
// poll everything until the call is cleared
while (!pollInCall(transaction,TCH)) { }
clearTransactionHistory(transaction);
}
/**
This function starts MOC on the SDCCH to the point of TCH assignment.
@param req The CM Service Request that started all of this.
@param LCH The logical used to initiate call setup.
*/
void Control::MOCStarter(const L3CMServiceRequest* req, LogicalChannel *LCH)
{
assert(LCH);
assert(req);
LOG(INFO) << "MOC: " << *req;
// Determine if very early assignment already happened.
bool veryEarly = (LCH->type()==FACCHType);
// If we got a TMSI, find the IMSI.
// Note that this is a copy, not a reference.
L3MobileIdentity mobileIdentity = req->mobileIdentity();
resolveIMSI(mobileIdentity,LCH);
// FIXME -- At this point, verify the that subscriber has access to this service.
// If the subscriber isn't authorized, send a CM Service Reject with
// cause code, 0x41, "requested service option not subscribed",
// followed by a Channel Release with cause code 0x6f, "unspecified".
// Otherwise, proceed to the next section of code.
// For now, we are assuming that the phone won't make a call if it didn't
// get registered.
// Allocate a TCH for the call, if we don't have it already.
TCHFACCHLogicalChannel *TCH = NULL;
if (!veryEarly) {
TCH = allocateTCH(dynamic_cast<SDCCHLogicalChannel*>(LCH));
// It's OK to just return on failure; allocateTCH cleaned up already,
// and the SIP side and transaction record don't exist yet.
if (TCH==NULL) return;
}
// Let the phone know we're going ahead with the transaction.
LOG(DEBUG) << "MOC: sending CMServiceAccept";
LCH->send(L3CMServiceAccept());
// Get the Setup message.
// GSM 04.08 5.2.1.2
L3Message* msg_setup = getMessage(LCH);
const L3Setup *setup = dynamic_cast<const L3Setup*>(msg_setup);
if (!setup) {
if (msg_setup) delete msg_setup;
throw UnexpectedMessage();
}
LOG(INFO) << "MOC: " << *setup;
// Pull out the L3 short transaction information now.
// See GSM 04.07 11.2.3.1.3.
unsigned L3TI = setup->TIValue();
if (!setup->haveCalledPartyBCDNumber()) {
// FIXME -- This is quick-and-dirty, not following GSM 04.08 5.
LOG(WARN) << "MOC setup with no number";
// Cause 0x60 "Invalid mandatory information"
LCH->send(L3ReleaseComplete(1,L3TI,L3Cause(0x60)));
LCH->send(L3ChannelRelease());
// The SIP side and transaction record don't exist yet.
// So we're done.
delete msg_setup;
return;
}
LOG(DEBUG) << "MOC: SIP start engine";
// Get the users sip_uri by pulling out the IMSI.
const char *IMSI = mobileIdentity.digits();
// Pull out Number user is trying to call and use as the sip_uri.
const char *bcd_digits = setup->calledPartyBCDNumber().digits();
// Create a transaction table entry so the TCH controller knows what to do later.
// The transaction on the TCH is a continuation of this one and uses the same ID.
TransactionEntry transaction(mobileIdentity,
req->serviceType(),
L3TI,
setup->calledPartyBCDNumber());
assert(transaction.TIFlag()==0);
transaction.SIP().User(IMSI);
transaction.Q931State(TransactionEntry::MOCInitiated);
LCH->transactionID(transaction.ID());
if (!veryEarly) TCH->transactionID(transaction.ID());
LOG(DEBUG) << "MOC: transaction: " << transaction;
gTransactionTable.add(transaction);
// At this point, we have enough information start the SIP call setup.
// We also have a SIP side and a transaction that will need to be
// cleaned up on abort or clearing.
// Now start a call by contacting asterisk.
// Engine methods will return their current state.
// The remote party will start ringing soon.
LOG(DEBUG) << "MOC: starting SIP (INVITE) Calling "<<bcd_digits;
unsigned basePort = allocateRTPPorts();
SIPState state = transaction.SIP().MOCSendINVITE(bcd_digits,gConfig.getStr("SIP.IP"),basePort,SIP::RTPGSM610);
LOG(DEBUG) << "MOC: SIP state="<<state;
LOG(DEBUG) << "MOC: Q.931 state=" << transaction.Q931State();
// Finally done with the Setup message.
delete msg_setup;
// The transaction is moving on to the MOCController.
// If we need a TCH assignment, we do it here.
gTransactionTable.update(transaction);
LOG(DEBUG) << "MOC: transaction: " << transaction;
if (veryEarly) {
// For very early assignment, we need a mode change.
static const L3ChannelMode mode(L3ChannelMode::SpeechV1);
LCH->send(L3ChannelModeModify(LCH->channelDescription(),mode));
L3Message *msg_ack = getMessage(LCH);
const L3ChannelModeModifyAcknowledge *ack =
dynamic_cast<L3ChannelModeModifyAcknowledge*>(msg_ack);
if (!ack) {
if (msg_ack) delete msg_ack;
throw UnexpectedMessage(transaction.ID());
}
// Cause 0x06 is "channel unacceptable"
bool modeOK = (ack->mode()==mode);
delete msg_ack;
if (!modeOK) return abortCall(transaction,LCH,L3Cause(0x06));
MOCController(transaction,dynamic_cast<TCHFACCHLogicalChannel*>(LCH));
} else {
// For late assignment, send the TCH assignment now.
// This dispatcher on the next channel will continue the transaction.
assignTCHF(transaction,dynamic_cast<SDCCHLogicalChannel*>(LCH),TCH);
}
}
/**
Continue MOC process on the TCH.
@param transaction The call state and SIP interface.
@param TCH The traffic channel to be used.
*/
void Control::MOCController(TransactionEntry& transaction, TCHFACCHLogicalChannel* TCH)
{
LOG(INFO) << "MOC: transaction: " << transaction;
unsigned L3TI = transaction.TIValue();
assert(transaction.TIFlag()==0);
assert(TCH);
// Once we can start SIP call setup, send Call Proceeding.
LOG(DEBUG) << "MOC: Sending Call Proceeding";
TCH->send(L3CallProceeding(1,L3TI));
transaction.Q931State(TransactionEntry::MOCProceeding);
gTransactionTable.update(transaction);
// Look for RINGING or OK from the SIP side.
// There's a T310 running on the phone now.
// The phone will initiate clearing if it expires.
while (transaction.Q931State()!=TransactionEntry::CallReceived) {
if (updateGSMSignalling(transaction,TCH)) return;
if (transaction.clearing()) return abortCall(transaction,TCH,L3Cause(0x7F));
LOG(INFO) << "MOC A: wait for Ringing or OK";
SIPState state = transaction.SIP().MOCWaitForOK();
LOG(DEBUG) << "MOC A: SIP state="<<state;
switch (state) {
case SIP::Busy:
LOG(INFO) << "MOC A: SIP:Busy, abort";
return abortCall(transaction,TCH,L3Cause(0x11));
case SIP::Fail:
LOG(NOTICE) << "MOC A: SIP:Fail, abort";
return abortCall(transaction,TCH,L3Cause(0x7F));
case SIP::Ringing:
LOG(INFO) << "MOC A: SIP:Ringing, send Alerting and move on";
TCH->send(L3Alerting(1,L3TI));
transaction.Q931State(TransactionEntry::CallReceived);
break;
case SIP::Active:
LOG(DEBUG) << "MOC A: SIP:Active, move on";
transaction.Q931State(TransactionEntry::CallReceived);
break;
case SIP::Proceeding:
LOG(DEBUG) << "MOC A: SIP:Proceeding, send progress";
TCH->send(L3Progress(1,L3TI));
break;
case SIP::Timeout:
LOG(NOTICE) << "MOC A: SIP:Timeout, reinvite";
state = transaction.SIP().MOCResendINVITE();
break;
default:
LOG(NOTICE) << "MOC A: SIP unexpected state " << state;
break;
}
}
gTransactionTable.update(transaction);
// There's a question here of what entity is generating the "patterns"
// (ringing, busy signal, etc.) during call set-up. For now, we're ignoring
// that question and hoping the phone will make its own ringing pattern.
// Wait for the SIP session to start.
// There's a timer on the phone that will initiate clearing if it expires.
LOG(INFO) << "MOC: wait for SIP OKAY";
SIPState state = transaction.SIP().state();
while (state!=SIP::Active) {
LOG(DEBUG) << "MOC: wait for SIP session start";
state = transaction.SIP().MOCWaitForOK();
LOG(DEBUG) << "MOC: SIP state "<< state;
// check GSM state
if (updateGSMSignalling(transaction,TCH)) return;
if (transaction.clearing()) return abortCall(transaction,TCH,L3Cause(0x7F));
// parse out SIP state
switch (state) {
case SIP::Busy:
// Should this be possible at this point?
LOG(INFO) << "MOC B: SIP:Busy, abort";
return abortCall(transaction,TCH,L3Cause(0x11));
case SIP::Fail:
LOG(INFO) << "MOC B: SIP:Fail, abort";
return abortCall(transaction,TCH,L3Cause(0x7F));
case SIP::Proceeding:
LOG(DEBUG) << "MOC B: SIP:Proceeding, NOT sending progress";
//TCH->send(L3Progress(1,L3TI));
break;
// For these cases, do nothing.
case SIP::Timeout:
// FIXME We should abort if this happens too often.
// For now, we are relying on the phone, which may have bugs of its own.
case SIP::Active:
default:
break;
}
}
gTransactionTable.update(transaction);
// Let the phone know the call is connected.
LOG(INFO) << "MOC: sending Connect to handset";
TCH->send(L3Connect(1,L3TI));
transaction.T313().set();
transaction.Q931State(TransactionEntry::ConnectIndication);
gTransactionTable.update(transaction);
// The call is open.
transaction.SIP().MOCInitRTP();
transaction.SIP().MOCSendACK();
// Get the Connect Acknowledge message.
while (transaction.Q931State()!=TransactionEntry::Active) {
LOG(DEBUG) << "MOC Q.931 state=" << transaction.Q931State();
if (updateGSMSignalling(transaction,TCH,T313ms)) return abortCall(transaction,TCH,L3Cause(0x7F));
}
// At this point, everything is ready to run the call.
gTransactionTable.update(transaction);
callManagementLoop(transaction,TCH);
// The radio link should have been cleared with the call.
// So just return.
}
void Control::MTCStarter(TransactionEntry& transaction, LogicalChannel *LCH)
{
assert(LCH);
LOG(INFO) << "MTC on " << LCH->type() << " transaction: "<< transaction;
// Determine if very early assigment already happened.
bool veryEarly = false;
if (LCH->type()==FACCHType) veryEarly=true;
// Allocate a TCH for the call.
TCHFACCHLogicalChannel *TCH = NULL;
if (!veryEarly) {
TCH = allocateTCH(dynamic_cast<SDCCHLogicalChannel*>(LCH));
// It's OK to just return on failure; allocateTCH cleaned up already.
// The orphaned transaction will be cleared automatically later.
if (TCH==NULL) return;
}
// Get transaction identifiers.
// This transaction was created by the SIPInterface when it
// processed the INVITE that started this call.
if (!veryEarly) TCH->transactionID(transaction.ID());
LCH->transactionID(transaction.ID());
unsigned L3TI = transaction.TIValue();
assert(transaction.TIFlag()==1);
// GSM 04.08 5.2.2.1
LOG(INFO) << "MTC: sending GSM Setup to call " << transaction.calling();
LCH->send(L3Setup(0,L3TI,L3CallingPartyBCDNumber(transaction.calling())));
transaction.T303().set();
transaction.Q931State(TransactionEntry::CallPresent);
gTransactionTable.update(transaction);
// Wait for Call Confirmed message.
LOG(DEBUG) << "MTC: wait for GSM Call Confirmed";
while (transaction.Q931State()!=TransactionEntry::MTCConfirmed) {
if (transaction.SIP().MTCSendTrying()==SIP::Fail) {
LOG(NOTICE) << "MTC: call failed on SIP side";
LCH->send(RELEASE);
// Cause 0x03 is "no route to destination"
return abortCall(transaction,LCH,L3Cause(0x03));
}
// FIXME -- What's the proper timeout here?
// It's the SIP TRYING timeout, whatever that is.
if (updateGSMSignalling(transaction,LCH,1000)) {
LOG(INFO) << "MTC: Release from GSM side";
LCH->send(RELEASE);
return;
}
// Check for SIP cancel, too.
if (transaction.SIP().MTCWaitForACK()==SIP::Fail) {
LOG(NOTICE) << "MTC: call failed on SIP side";
LCH->send(RELEASE);
// Cause 0x10 is "normal clearing"
return abortCall(transaction,LCH,L3Cause(0x10));
}
}
// The transaction is moving to the MTCController.
// Once this update happens, don't change the transaction object again in this function.
gTransactionTable.update(transaction);
LOG(DEBUG) << "MTC: transaction: " << transaction;
if (veryEarly) {
// For very early assignment, we need a mode change.
static const L3ChannelMode mode(L3ChannelMode::SpeechV1);
LCH->send(L3ChannelModeModify(LCH->channelDescription(),mode));
L3Message* msg_ack = getMessage(LCH);
const L3ChannelModeModifyAcknowledge *ack =
dynamic_cast<L3ChannelModeModifyAcknowledge*>(msg_ack);
if (!ack) {
if (msg_ack) delete msg_ack;
throw UnexpectedMessage(transaction.ID());
}
// Cause 0x06 is "channel unacceptable"
bool modeOK = (ack->mode()==mode);
delete msg_ack;
if (!modeOK) return abortCall(transaction,LCH,L3Cause(0x06));
MTCController(transaction,dynamic_cast<TCHFACCHLogicalChannel*>(LCH));
}
else {
// For late assignment, send the TCH assignment now.
// This dispatcher on the next channel will continue the transaction.
assignTCHF(transaction,dynamic_cast<SDCCHLogicalChannel*>(LCH),TCH);
}
}
void Control::MTCController(TransactionEntry& transaction, TCHFACCHLogicalChannel* TCH)
{
// Early Assignment Mobile Terminated Call.
// Transaction table in 04.08 7.3.3 figure 7.10a
LOG(DEBUG) << "MTC: transaction: " << transaction;
unsigned L3TI = transaction.TIValue();
assert(transaction.TIFlag()==1);
assert(TCH);
// Get the alerting message.
LOG(INFO) << "MTC:: waiting for GSM Alerting and Connect";
while (transaction.Q931State()!=TransactionEntry::Active) {
if (updateGSMSignalling(transaction,TCH,1000)) return;
if (transaction.Q931State()==TransactionEntry::Active) break;
if (transaction.Q931State()==TransactionEntry::CallReceived) {
LOG(DEBUG) << "MTC:: sending SIP Ringing";
transaction.SIP().MTCSendRinging();
}
// Check for SIP cancel, too.
if (transaction.SIP().MTCWaitForACK()==SIP::Fail) {
return abortCall(transaction,TCH,L3Cause(0x7F));
}
}
gTransactionTable.update(transaction);
LOG(INFO) << "MTC:: allocating port and sending SIP OKAY";
unsigned RTPPorts = allocateRTPPorts();
SIPState state = transaction.SIP().MTCSendOK(RTPPorts,SIP::RTPGSM610);
while (state!=SIP::Active) {
LOG(DEBUG) << "MTC: wait for SIP OKAY-ACK";
if (updateGSMSignalling(transaction,TCH)) return;
state = transaction.SIP().MTCWaitForACK();
LOG(DEBUG) << "MTC: SIP call state "<< state;
switch (state) {
case SIP::Active:
break;
case SIP::Fail:
return abortCall(transaction,TCH,L3Cause(0x7F));
case SIP::Timeout:
state = transaction.SIP().MTCSendOK(RTPPorts,SIP::RTPGSM610);
break;
case SIP::Connecting:
break;
default:
LOG(NOTICE) << "MTC: SIP unexpected state " << state;
break;
}
}
transaction.SIP().MTCInitRTP();
gTransactionTable.update(transaction);
// Send Connect Ack to make it all official.
LOG(DEBUG) << "MTC send GSM Connect Acknowledge";
TCH->send(L3ConnectAcknowledge(0,L3TI));
// At this point, everything is ready to run for the call.
// The radio link should have been cleared with the call.
gTransactionTable.update(transaction);
callManagementLoop(transaction,TCH);
}
void Control::EmergencyCall(const L3CMServiceRequest* req, LogicalChannel *LCH)
{
assert(req);
LOG(ALARM) << "starting emergency call from request " << *req;
assert(LCH);
TCHFACCHLogicalChannel* TCH = dynamic_cast<TCHFACCHLogicalChannel*>(LCH);
assert(TCH);
// If we got a TMSI, find the IMSI.
L3MobileIdentity mobileIdentity = req->mobileIdentity();
if (mobileIdentity.type()==TMSIType) {
const char *IMSI = gTMSITable.find(mobileIdentity.TMSI());
if (IMSI) mobileIdentity = L3MobileIdentity(IMSI);
}
// Can't find the TMSI? Ask for an IMSI.
if (mobileIdentity.type()==TMSIType) {
LOG(NOTICE) << "E-MOC with no IMSI or IMEI. Reqesting IMSI.";
TCH->send(L3IdentityRequest(IMSIType));
// FIXME -- This request times out on T3260, 12 sec. See GSM 04.08 Table 11.2.
L3Message* msg_resp = getMessage(TCH);
L3IdentityResponse *resp = dynamic_cast<L3IdentityResponse*>(msg_resp);
if (!resp) {
if (msg_resp) delete msg_resp;
throw UnexpectedMessage();
}
mobileIdentity = resp->mobileID();
delete msg_resp;
}
// Still no valid ID?? Get the IMEI.
if (mobileIdentity.type()==TMSIType) {
LOG(NOTICE) << "E-MOC with no IMSI or IMEI. Reqesting IMEI.";
TCH->send(L3IdentityRequest(IMSIType));
// FIXME -- This request times out on T3260, 12 sec. See GSM 04.08 Table 11.2.
L3Message* msg_resp = getMessage(TCH);
L3IdentityResponse *resp = dynamic_cast<L3IdentityResponse*>(msg_resp);
if (!resp) {
if (msg_resp) delete msg_resp;
throw UnexpectedMessage();
}
mobileIdentity = resp->mobileID();
delete msg_resp;
}
// Still no valid ID??? F*, just make something up!
if (mobileIdentity.type()==TMSIType) {
LOG(WARN) << "E-MOC with no identity, forcing to null IMSI.";
mobileIdentity = L3MobileIdentity("000000000000000");
}
// Let the phone know we're going ahead with the transaction.
LOG(NOTICE) << "E-MOC: sending CMServiceAccept";
TCH->send(L3CMServiceAccept());
// Get the Setup message.
L3Message* msg_setup = getMessage(TCH);
const L3EmergencySetup *setup = dynamic_cast<const L3EmergencySetup*>(msg_setup);
if (!setup) {
if (msg_setup) delete msg_setup;
throw UnexpectedMessage();
}
LOG(NOTICE) << "E-MOC: " << *setup;
// Pull out the L3 short transaction information now.
// See GSM 04.07 11.2.3.1.3.
unsigned L3TI = setup->TIValue();
// Make a copy. Don't forget to delete it later.
char *bcd_digits = strdup(gConfig.getStr("PBX.Emergency"));
LOG(DEBUG) << "E-MOC: SIP start engine";
// Create a transaction table entry so the TCH controller knows what to do later.
// The transaction on the TCH is a continuation of this one and uses the same ID
TransactionEntry transaction(mobileIdentity,
req->serviceType(),
L3TI, L3CalledPartyBCDNumber(bcd_digits));
assert(transaction.TIFlag()==0);
if (mobileIdentity.type()!=TMSIType) transaction.SIP().User(mobileIdentity.digits());
transaction.Q931State(TransactionEntry::MOCInitiated);
TCH->transactionID(transaction.ID());
LOG(DEBUG) << "E-MOC: transaction: " << transaction;
gTransactionTable.add(transaction);
// Done with the setup message.
delete msg_setup;
// Now start a call by contacting asterisk.
// Engine methods will return their current state.
// The remote party will start ringing soon.
LOG(DEBUG) << "E-MOC: starting SIP (INVITE) Calling "<<bcd_digits;
unsigned basePort = allocateRTPPorts();
SIPState state = transaction.SIP().MOCSendINVITE(bcd_digits,gConfig.getStr("SIP.IP"),basePort,SIP::RTPGSM610);
LOG(DEBUG) << "E-MOC: SIP state="<<state;
LOG(DEBUG) << "E-MOC: Q.931 state=" << transaction.Q931State();
free(bcd_digits);
// For very early assignment, we need a mode change.
static const L3ChannelMode mode(L3ChannelMode::SpeechV1);
TCH->send(L3ChannelModeModify(TCH->channelDescription(),mode));
L3Message *msg_ack = getMessage(TCH);
const L3ChannelModeModifyAcknowledge *ack =
dynamic_cast<L3ChannelModeModifyAcknowledge*>(msg_ack);
if (!ack) {
if (msg_ack) delete msg_ack;
throw UnexpectedMessage(transaction.ID());
}
// Cause 0x06 is "channel unacceptable"
bool modeOK = (ack->mode()==mode);
delete msg_ack;
if (!modeOK) return abortCall(transaction,TCH,L3Cause(0x06));
// From here on, it's normal call setup.
MOCController(transaction,TCH);
}
void Control::TestCall(TransactionEntry& transaction, LogicalChannel *LCH)
{
assert(LCH);
LOG(INFO) << LCH->type() << " transaction: "<< transaction;
// Mark the call as active.
transaction.Q931State(TransactionEntry::Active);
gTransactionTable.update(transaction);
// Create and open the control port.
UDPSocket controlSocket(gConfig.getNum("TestCall.Port"));
// If this is a FACCH, change the mode from signaling-only to speech.
if (LCH->type()==FACCHType) {
static const L3ChannelMode mode(L3ChannelMode::SpeechV1);
LCH->send(L3ChannelModeModify(LCH->channelDescription(),mode));
L3Message *msg_ack = getMessage(LCH);
const L3ChannelModeModifyAcknowledge *ack =
dynamic_cast<L3ChannelModeModifyAcknowledge*>(msg_ack);
if (!ack) {
if (msg_ack) delete msg_ack;
controlSocket.close();
throw UnexpectedMessage(transaction.ID());
}
// Cause 0x06 is "channel unacceptable"
bool modeOK = (ack->mode()==mode);
delete msg_ack;
if (!modeOK) {
controlSocket.close();
return abortCall(transaction,LCH,L3Cause(0x06));
}
}
unsigned L3TI = transaction.TIValue();
assert(transaction.TIFlag()==1);
unsigned RTPPorts = allocateRTPPorts();
// FIXME -- Somehow, the RTP ports need to be attached to the transaction.
// This loop will run or block until some outside entity writes a
// channel release on the socket.
LOG(INFO) << "entering test loop";
while (true) {
// Get the outgoing message from the test call port.
char iBuf[MAX_UDP_LENGTH];
int msgLen = controlSocket.read(iBuf);
LOG(INFO) << "got " << msgLen << " bytes on UDP";
// Send it to the handset.
L3Frame query(iBuf,msgLen);
LOG(INFO) << "sending " << query;
LCH->send(query);
// Wait for a response.
// FIXME -- This should be a proper T3xxx value of some kind.
L3Frame* resp = LCH->recv(30000);
if (!resp) {
LOG(NOTICE) << "read timeout";
break;
}
if (resp->primitive() != DATA) {
LOG(NOTICE) << "unexpected primitive " << resp->primitive();
break;
}
LOG(INFO) << "received " << *resp;
// Send response on the port.
unsigned char oBuf[resp->size()];
resp->pack(oBuf);
controlSocket.writeBack((char*)oBuf);
// Delete and close the loop.
delete resp;
}
controlSocket.close();
LOG(INFO) << "ending";
LCH->send(L3ChannelRelease());
LCH->send(RELEASE);
clearTransactionHistory(transaction);
}
void Control::initiateMTTransaction(TransactionEntry& transaction, GSM::ChannelType chanType, unsigned pageTime)
{
gTransactionTable.add(transaction);
gBTS.pager().addID(transaction.subscriber(),chanType,transaction,pageTime);
}
// vim: ts=4 sw=4
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