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El sáb, 21-11-2015 a las 01:17 +0000, Kale, Rahul escribió:
<BLOCKQUOTE TYPE=CITE>
<BR>
<BR>
Hello,<BR>
</BLOCKQUOTE>
<BR>
Hi Kale,<BR>
<BR>
<BLOCKQUOTE TYPE=CITE>
We are using the latest published version of noPoll. <BR>
</BLOCKQUOTE>
<BR>
Ok,<BR>
<BR>
<BLOCKQUOTE TYPE=CITE>
Your suggestion of blocking nopoll_conn_wait_until_connection_ready would not fix the <BR>
issue since the SSL_connect() returns error well before that (SSL_ERROR_SYSCALL).<BR>
</BLOCKQUOTE>
<BR>
Ok,<BR>
<BR>
<BLOCKQUOTE TYPE=CITE>
As I mentioned in the original report, I had put a small timeout as a workaround.<BR>
<BR>
However, when we started testing against a Websocket server a long distance away<BR>
(California, US to Belgium) the problem resurfaced. <BR>
<BR>
<BR>
<BR>
Yesterday, I spent some time digging into the problem further. Turns out that <BR>
if I increased the timeout to a large value (300 ms instead of 10 ms) the connection<BR>
starts working. I rationalized that if the TCP connect completes (3 way handshake)<BR>
<B>before</B> we hand the socket over to SSL/TLS for processing, the problem goes away.<BR>
<BR>
<BR>
<BR>
So now I implemented a new workaround. I wait for the TCP connection to complete<BR>
before telling SSL library the socket fd using SSL_set_fd().<BR>
<BR>
<BR>
<BR>
I modified nopoll_conn.c as follows:<BR>
<BR>
<BR>
<BR>
/* set socket */<BR>
<BR>
wait_for_socket_connect(conn->session); // workaround -- RPK<BR>
<BR>
SSL_set_fd (conn->ssl, conn->session);<BR>
<BR>
<BR>
<BR>
Where the wait_for_socket_connect is implemented as follows in nopoll_conn.c :<BR>
<BR>
<BR>
<BR>
staticint wait_for_socket_connect(int socketfd) <BR>
<BR>
{<BR>
<BR>
// On windows, when connect() is called on non-blocking call<BR>
<BR>
// connection succeeded if the socket is ready for writing<BR>
<BR>
fd_set write_fdset, except_fdset;<BR>
<BR>
struct timeval timeout;<BR>
<BR>
<BR>
<BR>
FD_ZERO(&write_fdset);<BR>
<BR>
FD_ZERO(&except_fdset);<BR>
<BR>
FD_SET((unsigned int) socketfd, &write_fdset );<BR>
<BR>
FD_SET((unsigned int) socketfd, &except_fdset );<BR>
<BR>
<BR>
<BR>
// Wait upto 2 seconds<BR>
<BR>
timeout.tv_sec = 0;<BR>
<BR>
timeout.tv_usec = 2000000;<BR>
<BR>
<BR>
<BR>
select( 0, NULL, &write_fdset, &except_fdset, &timeout);<BR>
<BR>
<BR>
<BR>
// connection failed<BR>
<BR>
if (FD_ISSET(socketfd, &except_fdset)) {<BR>
<BR>
return -1;<BR>
<BR>
}<BR>
<BR>
// successful connection<BR>
<BR>
else if (FD_ISSET(socketfd, &write_fdset)) {<BR>
<BR>
return 0;<BR>
<BR>
}<BR>
<BR>
return -1;<BR>
<BR>
}<BR>
</BLOCKQUOTE>
<BR>
And this solves the problem? Totally? ...or you are still experimenting errors? <BR>
<BR>
<BLOCKQUOTE TYPE=CITE>
It is very strange that this problem occurs only from the second connection using<BR>
the library. You should be able to reproduce the problem using the test program<BR>
I posted in the original report. <BR>
</BLOCKQUOTE>
<BR>
Ok, I'll look for a moment to review your test...<BR>
<BR>
<BLOCKQUOTE TYPE=CITE>
I understand that the OpenSSL library is supposed to<BR>
automatically take care of this and there should not be any need to wait<BR>
for the base TCP connection to be established beforehand. But for some reason it does not.<BR>
</BLOCKQUOTE>
<BR>
Certainly it does. We have used OpenSSL for many years in many different projects<BR>
and connection scenarios and we didn't face something similar as you describe...<BR>
...but as usual, there's a first time for everything,<BR>
<BR>
It can also be a noPoll's bug that some how causes that SYSCALL error at the TLS/SSL<BR>
level...dunno,<BR>
<BR>
<BLOCKQUOTE TYPE=CITE>
The above workaround is holding up for now but we would like to resolve this<BR>
properly.<BR>
</BLOCKQUOTE>
<BR>
Ok. I'll look for a moment to review your test. <BR>
<BR>
Best Regards,<BR>
<BR>
<BR>
<BR>
<BLOCKQUOTE TYPE=CITE>
Thanks,<BR>
<BR>
<BR>
<BR>
Rahul<BR>
<BR>
<BR>
<BR>
Rahul Kale<BR>
<BR>
<BR>
<BR>
IP Video Systems<BR>
<BR>
Barco, Inc<BR>
<BR>
1287 Anvilwood Ave<BR>
<BR>
Sunnyvale, CA 94089<BR>
<BR>
<BR>
<BR>
Tel +1 408 400 4238<BR>
<BR>
<BR>
<BR>
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<B>From:</B> Kale, Rahul <BR>
<B>Sent:</B> Thursday, November 19, 2015 3:14 PM<BR>
<B>To:</B> nopoll@lists.aspl.es<BR>
<B>Cc:</B> 'Francis Brosnan Blázquez'<BR>
<B>Subject:</B> RE: [noPoll] Issue with using Secure Sockets client connecion (wss://) from Windows<BR>
<BR>
<BR>
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<BR>
<BR>
<BR>
<BR>
Hello,<BR>
<BR>
<BR>
<BR>
Any resolution to the issue regarding this?<BR>
<BR>
In spite of the workaround mentioned below, we see this fail<BR>
in certain cases.<BR>
<BR>
<BR>
<BR>
Thanks,<BR>
<BR>
<BR>
<BR>
Rahul<BR>
<BR>
<BR>
<BR>
Rahul Kale<BR>
<BR>
<BR>
<BR>
IP Video Systems<BR>
<BR>
Barco, Inc<BR>
<BR>
1287 Anvilwood Ave<BR>
<BR>
Sunnyvale, CA 94089<BR>
<BR>
<BR>
<BR>
<BR>
<BR>
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<B>From:</B><A HREF="mailto:nopoll-bounces@lists.aspl.es">nopoll-bounces@lists.aspl.es</A> [<A HREF="mailto:nopoll-bounces@lists.aspl.es">mailto:nopoll-bounces@lists.aspl.es</A>] <B>On Behalf Of </B>Kale, Rahul<BR>
<B>Sent:</B> Tuesday, September 08, 2015 6:35 PM<BR>
<B>To:</B> <A HREF="mailto:nopoll@lists.aspl.es">nopoll@lists.aspl.es</A><BR>
<B>Subject:</B> [noPoll] Issue with using Secure Sockets client connecion (wss://) from Windows<BR>
<BR>
<BR>
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
<BR>
<BR>
<BR>
<BR>
Hello,<BR>
<BR>
<BR>
<BR>
I am facing an issue with using noPoll library for Secure Websockets (wss://)<BR>
<BR>
client connection on Windows platform. Basically, the first connection from<BR>
<BR>
the same binary works but subsequent connections do not work reliably.<BR>
<BR>
When I tried to debug the issue, by enabling logs, the problem goes away.<BR>
<BR>
Strangely, if I install my own log handler with an empty (do nothing)<BR>
<BR>
implementation, the problem also goes away.<BR>
<BR>
I have been trying to track down the problem the past week and finally have<BR>
<BR>
something to report.<BR>
<BR>
<BR>
<BR>
Firstly, I have isolated the code (see below) to the bare minimum below for you to reproduce the<BR>
<BR>
issue. The code makes 100 back to back connections in a loop and exits the loop<BR>
<BR>
early if it fails. This code rarely lasts for 2 or more loops. However if you <BR>
<BR>
enable logs (setting nopoll_log_set_handler to true) or install a log <BR>
<BR>
handler (using nopoll_log_set_handler), it will make 100 successful connections.<BR>
<BR>
<BR>
<BR>
Since logging did not help, I ended up compiling the noPoll source myself for further<BR>
<BR>
debugging. Since I am using VS 2008, I had to fix the code here and there to get it<BR>
<BR>
to compile and also had to add __declspec(dllexport) to most functions in the header file.<BR>
<BR>
By adding trial and error printfs I narrowed down the spot when it fails.<BR>
<BR>
Whenever the connect fails, the SSL_connect() function errors out with <BR>
<BR>
SSL_ERROR_SYSCALL at around line 756 in nopoll_conn.c.<BR>
<BR>
<BR>
<BR>
Assuming that there is some timing issue (since logging adds just enough delay), <BR>
<BR>
I have put a temporary fix as a workaround which fixes the issue: I added <BR>
<BR>
a nopoll_sleep() just before SSL_connect() like so:<BR>
<BR>
<BR>
<BR>
nopoll_sleep (10000);<BR>
<BR>
while (SSL_connect (conn->ssl) <= 0) {<BR>
<BR>
…<BR>
<BR>
<BR>
<BR>
<BR>
<BR>
I am sure you will find the root cause and have a better fix.<BR>
<BR>
<BR>
<BR>
Here is the sample code:<BR>
<BR>
<BR>
<BR>
#include "nopoll.h"<BR>
<BR>
<BR>
<BR>
static void noPollLogger(noPollCtx *ctx, noPollDebugLevel level, const char *log_msg, noPollPtr user_data) {<BR>
<BR>
// Do nothing here<BR>
<BR>
}<BR>
<BR>
<BR>
<BR>
int ConnectToWebsocket()<BR>
<BR>
{<BR>
<BR>
<BR>
<BR>
noPollCtx * context = nopoll_ctx_new();<BR>
<BR>
<BR>
<BR>
//nopoll_log_set_handler(context, noPollLogger, NULL);<BR>
<BR>
nopoll_log_enable(context, false);<BR>
<BR>
<BR>
<BR>
noPollConnOpts * opts = nopoll_conn_opts_new();<BR>
<BR>
nopoll_conn_opts_ssl_peer_verify(opts, false); // disable cert verification<BR>
<BR>
noPollConn * connection = nopoll_conn_tls_new(context, opts, "10.1.2.3", "443", NULL,<BR>
<BR>
"wss://10.1.2.3:443/wstunnel/?dst=127.0.0.1:6060", "tunnel-protocol", "some-origin");<BR>
<BR>
<BR>
<BR>
bool connected = true;<BR>
<BR>
int count = 0;<BR>
<BR>
while (!nopoll_conn_is_ready(connection)) {<BR>
<BR>
if (!nopoll_conn_is_ok(connection)) {<BR>
<BR>
connected = false;<BR>
<BR>
break;<BR>
<BR>
}<BR>
<BR>
nopoll_sleep(10000);<BR>
<BR>
fprintf(stdout, "Info: Waiting for connection...\n", count++);<BR>
<BR>
}<BR>
<BR>
<BR>
<BR>
if (connected) {<BR>
<BR>
fprintf(stdout, "Info: Connected!!\n");<BR>
<BR>
}<BR>
<BR>
else {<BR>
<BR>
fprintf(stdout, "Failed websocket connection\n");<BR>
<BR>
exit(1);<BR>
<BR>
}<BR>
<BR>
<BR>
<BR>
nopoll_conn_close(connection);<BR>
<BR>
nopoll_ctx_unref(context);<BR>
<BR>
<BR>
<BR>
return 0;<BR>
<BR>
}<BR>
<BR>
<BR>
<BR>
int main(int argc, char *argv[])<BR>
<BR>
{<BR>
<BR>
for (int i = 0; i < 100; i++) {<BR>
<BR>
ConnectToWebsocket();<BR>
<BR>
fprintf(stderr, "Done Loop %d\n", i);<BR>
<BR>
}<BR>
<BR>
return 0;<BR>
<BR>
}<BR>
<BR>
<BR>
<BR>
Thanks,<BR>
<BR>
<BR>
<BR>
Rahul<BR>
<BR>
<BR>
<BR>
Rahul Kale<BR>
<BR>
<BR>
<BR>
IP Video Systems<BR>
<BR>
Barco, Inc<BR>
<BR>
1287 Anvilwood Ave<BR>
<BR>
Sunnyvale, CA 94089<BR>
<BR>
<BR>
<BR>
Tel +1 408 400 4238<BR>
<BR>
<BR>
<BR>
This message is subject to the following terms and conditions: <A HREF="http://www.barco.com/en/maildisclaimer">MAIL DISCLAIMER</A> <BR>
<BR>
<BR>
</BLOCKQUOTE>
<BLOCKQUOTE TYPE=CITE>
This message is subject to the following terms and conditions: <A HREF="http://www.barco.com/en/maildisclaimer">MAIL DISCLAIMER</A><BR>
</BLOCKQUOTE>
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