PR_Read fails second time on Solaris 8

[VinuT]

Hi,

We are using NSPR/NSS for SSL communication on Solaris8.

Right now, we are using it as a client to communicate to another SSL server
running on windows.
However my PR_Read call returns with 0, when its called a second time.
The first calls succeeds and returns me some data in the buffer.

Can anybody throw some light as to what is going wrong here?

Thanks
Vinu

[Nelson Bolyard]

Are you sure that anything is wrong?
Is it possible that the first buffer contained all the data from the server?
Did the server send you the data and then close the connection?

If you're not sure, try using ssltap.

[Vinu]

Yes, the server sent me all the data and then closed the connection.

And NSPR should have received all the data and stored in its buffers.
The returned the data to the client application through PR_Read.
But this is not happening because PR_Read returns 0, even though it should
have more data in its buffers.

We have the exact same code on Windows and there NSPR seems to work fine.
i.e PR_Read returns data properly.

Thanks
Vinu

"Nelson Bolyard" <NOnels...@NObolyardSPAM.me> wrote in message
news:hbCdnU0a9KlFUoTX...@mozilla.org...

[Vinu]

Hi Nelson,

Yes, I did some more tests.

The server sends the data and then closes the connection(becuase we use HTTP
Connection:close and not Keep-Alive).

But shouldnt PR_Read return the entire data and then only return 0(becuase
the connection is closed).
How can it return 0, before all the data has been returned to the
application.

BTW this same code on Linux and Windows works fine.

Thanks
Vinu

"Nelson Bolyard" <NOnels...@NObolyardSPAM.me> wrote in message
news:hbCdnU0a9KlFUoTX...@mozilla.org...

[Wan-Teh Chang]

On Wed, May 27, 2009 at 3:26 PM, Vinu <vinu....@pass-consulting.com> wrote:
> Hi Nelson,
>
> Yes, I did some more tests.
>
> The server sends the data and then closes the connection(becuase we use HTTP
> Connection:close and not Keep-Alive).
>
> But shouldnt PR_Read return the entire data and then only return 0(becuase
> the connection is closed).
> How can it return 0, before all the data has been returned to the
> application.
>
> BTW this same code on Linux and Windows works fine.

I'm afraid that you'll need to debug this yourself because we
can't reproduce this problem. The relevant file is
mozilla/nsprpub/pr/src/pthreads/ptio.c. Look at pt_Recv and
pt_recv_cont.

The implementation of PR_Read is essentially the same between
Solaris and Linux, with one difference -- as a performance optimization,
we use read() instead of recv() on Solaris only. See:
http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/nsprpub/pr/src/pthreads/ptio.c&rev=3.113&mark=1858,1863,1865#1830
http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/nsprpub/pr/src/pthreads/ptio.c&rev=3.113&mark=779,786,789#772

Please try changing those two instances of
#if defined(SOLARIS)
to
#if defined(SOLARIS_X)
(which disables the Solaris code), and rebuild NSPR. Does that
make the problem go away on Solaris?

If that fixes the problem, I have to admit that I don't understand
why because read() should also work with sockets.

If that doesn't fix the problem, you can add printf statements
or use a debugger to find out what the read() or recv() calls
return, etc.

Wan-Teh

[VinuT]

This problem is not due to NSPR. We have identified it as a source in SSL
server

I tried using the suggestions below i.e
#if defined(SOLARIS_X)
and icluding recv instead of read.
but i still got same behaviour.

So i did a packet capture on the SSL server and saw that the server was
sending TCP FIN,ACK packets in between.
When it did this, PR_Read would return without the complete data.
However if the server sends a ACK,ACK packet, everything seems fine.

And we tested it against some other SSL servers running on different
machines. There everything seems to work fine.

Thanks for your help Wan-Teh and everyone

"Wan-Teh Chang" <w...@google.com> wrote in message
news:mailman.249.124346690...@lists.mozilla.org...