OCC5.2 installation try to connect to internet host !!


Why at the beginning of OCC5.2 Windows installation the java virtual machine try to communicate with host ra.thunderworx.net on port UDP ?

Is it like one of those spywares ?

My configuration is : Windows XP Pro SP1 + MS recommended security patch.

Jean Michel.

JeanmiB's picture

I investigate a similar problem when I realize that each first time I execute Data Exchange Draw commands, the process tries to connect to a DNS server to resolve some internet adress.

In fact, if you look at source code "IGESData::Init()", there is a variable declared "OSD_Host host". Then at looking at the source code of the constructor of OSD_Host, it makes some stuff (only once per TKernel instance running) in order to identifies the hostname and its IP adress.

Unfortunately it uses the function "gethostbyname" from the wsock32.lib.

1/ This function returns the IP adress of the host by looking at a host database. In my case, a computer at home, so generally it will connect to the DNS server of my ISP, instead of resolving the netbios name.

2/ this method has been deprecated by Microsoft with the introduction of the getaddrinfo function. see http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winsock...

3/ Some firewalls blocks the usage of gethostbyname because this function is not secure and was one of the weakness exploited by Sasser

This explanation may responds to an older message in this forum saying that OpenCascade was sometimes connecting to the internet while running.

This could easily be corrected quickly by removing the sentence "OSD_Host host" in "IGESData:Init()" because it is never used (People from OCC will correct me if I'm wrong).

I still don't know if it's related to my initial problem of installation.
I hope OCC developers could analyze the initial problem and make some answers, because the strange thing is that TKIges was really connecting to my ISP whereas Installation program was connecting to a foreign host which I don't know.

Jean Michel

Open CASCADE Support Team's picture

Dear Jean-Michel,

Thank you for your profound analysis and for your suggestion to eliminate this problem in Open CASCADE Technology!

We are pleased to inform you that you contribution has been registered as improvement with reference number OCC7706 "IGES translator accesses DNS without a need".

The correction you suggested will be further processed with a view for integration into future releases of OCCT.

Please note that you will be able to track integration of that improvement consulting the Release Notes of Open CASCADE Technology. The Release Notes are regularly published on our web site at http://www.opencascade.org/getocc/whatsnew.

We remind to all members of the Community that we value your efforts and we are always glad to receive your helpful contributions.

Yours sincerely,
Open CASCADE Support Team