Re: [reSIProcate-users] branch not unique in reinvites

[Scott Godin <sgodin@xxxxxxxxxxxxxxx>]

Interesting - I remember a while back, we had trouble understanding why some OS's where seeing problems and other were not.  If I remember correctly someone ended up working around this issue using the OpenSSL random number generator - but I'm not sure what kind of performance hit this has.

Please keep us updated to your progress. : )

Thanks,

Scott

On Wed, Nov 24, 2010 at 4:41 PM, Vasanthi Ramasamy <Vasanthi.Ramasamy@xxxxxxxxxx> wrote:

We are using Linux RedHat 5 and there is  seriously an insufficient randomness issue. Look at the given code (uses the logic from  Resiprocate source code).  I see that the random numbers generated are repeated in re-invite scenario between 200 – 300 millsecs., leading to branch/transaction-ids not unique.

 

Trying to come up something using Boost library’s random number generators at this point. Resiprocate developers have to definitely think of something for this issue.   

 

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

#include <unistd.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <sys/time.h>

#include <unistd.h>

#include <map>

#include <iostream>

 

typedef unsigned long long UInt64;

using namespace std;

 

UInt64 getSystemTime() {

    struct timeval now;

       UInt64 time=0;

    gettimeofday( &now , NULL );

    time = now.tv_sec;

    time = time*1000000;

    time += now.tv_usec;

    return time;

}

 

int main() {

         map<int, int> random_map;

 

         unsigned int seed = static_cast<unsigned int> (getSystemTime()/1000LL);

         srandom(seed);

 

 

         int fd = open("/dev/urandom", O_RDONLY);

         if ( fd != -1 )

         {

            int s = read( fd,&seed,sizeof(seed) ); //!ah! blocks if /dev/random on embedded sys

 

            if ( s != sizeof(seed) )

            {

               cout  << "System is short of randomness" << endl ; // !ah! never prints

            }

            ::close(fd);

         }

         else

         {

            cout << "Could not open /dev/urandom" ;

         }

 

 

        for (int i = 0;  i < 100000; i++) {

                pair<map<int, int>::iterator,bool> ret;

                int rand = random();

                ret=random_map.insert(make_pair(rand, 0));

                if (ret.second==false)

                {

                        cout << "ERROR !!! sizeofmap:" << random_map.size() << endl;

                        break;

                }

        }

        random_map.clear();

        return 0;

}

 

 

 

From: Jeremy Geras [mailto:jgeras@xxxxxxxxxxxxxxx]
Sent: Wednesday, November 24, 2010 11:54 AM
To: Vasanthi Ramasamy; Scott Godin

Cc: resiprocate-users@xxxxxxxxxxxxxxx

Subject: RE: [reSIProcate-users] branch not unique in reinvites

 

We've hit this before as well -- it manifested itself in our unit tests, where generation of branch parameters, etc., happens more frequently than in typical real-life usage.

 

I've attached our version of Random which uses RtlGenRandom on Windows to get around the insufficient randomness issue.

 

(Note that this fix is sitting around on our last contrib branch at https://svn.resiprocate.org/rep/resiprocate/branches/b-ctpc-fixes-20090113 -- the branch is somewhat old, but nonetheless if anyone has time to give it a review then maybe we can merge it to mainline...)

 

Jeremy

---

From: resiprocate-users-bounces@xxxxxxxxxxxxxxx [resiprocate-users-bounces@xxxxxxxxxxxxxxx] on behalf of Vasanthi Ramasamy [Vasanthi.Ramasamy@xxxxxxxxxx]
Sent: Wednesday, November 24, 2010 6:12 AM
To: Scott Godin
Cc: resiprocate-users@xxxxxxxxxxxxxxx
Subject: Re: [reSIProcate-users] branch not unique in reinvites

Yes I’m using provideOffer().

 

I’m looking at the random number generation code in rutil/Random.cxx  to crack it down.  I will update you with my findings.

 

From: slgodin@xxxxxxxxx [mailto:slgodin@xxxxxxxxx] On Behalf Of Scott Godin
Sent: Wednesday, November 24, 2010 9:10 AM
To: Vasanthi Ramasamy
Cc: resiprocate-users@xxxxxxxxxxxxxxx
Subject: Re: [reSIProcate-users] branch not unique in reinvites

 

That doesn't sound right - resip will automatically generate a new via for each outbound request.  I don't remember any known issues with this in the past.  Are you using DUM and the provideOffer API to send the re-invite?

On Tue, Nov 23, 2010 at 2:21 PM, Vasanthi Ramasamy <Vasanthi.Ramasamy@xxxxxxxxxx> wrote:

Hi,

I'm trying to test re-invite scenario using Resiprocate and I see this behavior where branch in Via is not unique (leading to lots of issues). In a re-invited scenario, where my application sends a reinvite, it uses the same branch in Via, either for the re-invite or for the ACK generated for the re-invite (in response to 200 OK from remote end) for calls which are totally un-related. Am I missing anything here ? How can I make resiprocate to create a unique branch for Via ?

I'm using Resiprocate 1.5

Thanks,
Vasanthi
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