[h323plus] H323EndPoint::InternalMakeCall bug

Simon Horne s.horne at packetizer.com
Sun Jan 3 05:37:14 EST 2016


Iurii

 

Fix checked into CVS.

 

Simon

 

From: h323plus [mailto:h323plus-bounces at lists.packetizer.com] On Behalf Of Iurii Gordiienko
Sent: Thursday, December 31, 2015 8:40 PM
To: h323plus at lists.packetizer.com
Subject: [h323plus] H323EndPoint::InternalMakeCall bug

 

Hi,

 

I have found an issue with H323EndPoint::InternalMakeCall function for case when it running from H323EndPoint::ForwardConnection function (may be for some others cases too).

Take a look:

1.We are trying to connect to some host which uses Gatekeeper.

2.From H323EndPoint::ForwardConnection call H323EndPoint::InternalMakeCall function with some internal token="ip$xxx.xxx.xxx.xxx/port"

3.In the body of H323EndPoint::InternalMakeCall we have the replacement current callToken-connection pair to new one with "ip$xxx.xxx.xxx.xxx/port-replaced-1" string, like

    

    connectionsActive.SetAt(adjustedToken, connectionsActive.RemoveAt(newToken));

    connectionsToBeCleaned += adjustedToken;

 

4.But if for some reason our virtual CreateConnection function returns NULL...

 

  connection = CreateConnection(lastReference, userData, transport, NULL);

  if (connection == NULL) {

    PTRACE(1, "H323\tCreateConnection returned NULL");

    connectionsMutex.Signal();

 

    return NULL;

  }

 

 ... we cannot clear current Connection because it has not actual callToken "ip$xxx.xxx.xxx.xxx/port" but H323EndPoint::connectionsActive has "ip$xxx.xxx.xxx.xxx/port-replaced-1" and endpoint.ClearCall(callToken, reason) or something similar will be failed because not able to found the Connection by own callToken.

 

5.Also we have redundant call connectionsMutex.Signal().

 

if (connection == NULL) {

    PTRACE(1, "H323\tCreateConnection returned NULL");

    connectionsMutex.Signal();

 

    return NULL;

  }

 

 

My proposition - just rename back callToken for H323EndPoint::connectionsActive and remove adjustedToken from H323EndPoint::connectionsToBeCleaned if we have NULL connection.

My H323EndPoint::InternalMakeCall function looks like this:

 

H323Connection * H323EndPoint::InternalMakeCall(const PString & trasferFromToken,

                                                const PString & callIdentity,

                                                unsigned capabilityLevel,

                                                const PString & remoteParty,

                                                H323Transport * transport,

                                                PString & newToken,

                                                void * userData,

                                                PBoolean supplimentary

                                                )

{

  PTRACE(2, "H323\tMaking call to: " << remoteParty);

 

  PString alias;

  H323TransportAddress address;

  if (!ParsePartyName(remoteParty, alias, address)) {

    PTRACE(2, "H323\tCould not parse \"" << remoteParty << '"');

    return NULL;

  }

 

#ifdef H323_H46017

  // If H.460.17 use the existing H.460.17 Transport

  if (transport == NULL && RegisteredWithH46017())

      transport = GetH46017Transport();

#endif

 

  if (transport == NULL) {

    // Restriction: the call must be made on the same transport as the one

    // that the gatekeeper is using.

    if (gatekeeper != NULL)

      transport = gatekeeper->GetTransport().GetRemoteAddress().CreateTransport(*this);

 

    // assume address is an IP address/hostname

    else

      transport = address.CreateTransport(*this);

 

    if (transport == NULL) {

      PTRACE(1, "H323\tInvalid transport in \"" << remoteParty << '"');

      return NULL;

    }

  }

 

  H323Connection * connection;

 

  connectionsMutex.Wait();

 

  PString adjustedToken;

  unsigned lastReference;

  if (newToken.IsEmpty()) {

    do {

      lastReference = Q931::GenerateCallReference();

      newToken = BuildConnectionToken(*transport, lastReference, FALSE);

    } while (connectionsActive.Contains(newToken));

  }

  else {

    lastReference = newToken.Mid(newToken.Find('/')+1).AsUnsigned();

 

    // Move old connection on token to new value and flag for removal

    unsigned tieBreaker = 0;

    do {

      adjustedToken = newToken + "-replaced";

      adjustedToken.sprintf("-%u", ++tieBreaker);

    } while (connectionsActive.Contains(adjustedToken));

    connectionsActive.SetAt(adjustedToken, connectionsActive.RemoveAt(newToken));

    connectionsToBeCleaned += adjustedToken;

    PTRACE(3, "H323\tOverwriting call " << newToken << ", renamed to " << adjustedToken);

  }

  connectionsMutex.Signal();

 

  connection = CreateConnection(lastReference, userData, transport, NULL);

  if (connection == NULL) {

    PTRACE(1, "H323\tCreateConnection returned NULL");

    

    if (!adjustedToken.IsEmpty())

    {

        connectionsMutex.Wait();

 

        connectionsActive.SetAt(newToken, connectionsActive.RemoveAt(adjustedToken));

        connectionsToBeCleaned -= adjustedToken;

 

        PTRACE(3, "H323\tOverwriting call " << adjustedToken << ", renamed to " << newToken);

 

        connectionsMutex.Signal();

    }

 

    return NULL;

  }

  connection->SetRemotePartyName(remoteParty);

 

  if (supplimentary) 

      connection->SetNonCallConnection();     

 

  connection->Lock();

 

  connectionsMutex.Wait();

  connectionsActive.SetAt(newToken, connection);

 

  connectionsMutex.Signal();

 

  connection->AttachSignalChannel(newToken, transport, FALSE);

 

#ifdef H323_H450

  if (capabilityLevel == UINT_MAX)

    connection->HandleTransferCall(trasferFromToken, callIdentity);

  else {

    connection->HandleIntrudeCall(trasferFromToken, callIdentity);

    connection->IntrudeCall(capabilityLevel);

  }

#endif

 

  PTRACE(3, "H323\tCreated new connection: " << newToken);

 

#ifdef H323_H46017

  if (RegisteredWithH46017()) {

    H323Connection::CallEndReason reason = connection->SendSignalSetup(alias, address);

    if (reason != H323Connection::NumCallEndReasons)

      connection->ClearCall(reason);

  } else

#endif

      new H225CallThread(*this, *connection, *transport, alias, address);

 

  return connection;

}

 

 

 

 

Thanks

--

Iurii Gordiienko

  <https://mail.ukr.net/api/public/message_read?a=nKmgvdFnKHmsk7uvZLEpXiblD9YyE83lU1NJebnGIxeofEcS2srd_e9yhYiMfmjk2T54SqWV9K_Bl-5oL7JgA0S8p5TmQW9gUdNY_EoDH8w=> 

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