in reply to Re: Help with socket connections
in thread Help with socket connections

Great idea, but it doesn't seem to work. I also tried this: 
while (IO::Socket::connected($local_client) and recv ($local_client,$e
+,1,0)) { print $e; last unless
 IO::Socket::connected($local_client) };

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And it didn't seem to have any effect at all. The TCP sessions themselves are getting stuck in a wibbly-wobbly world. Even after the remote side gets tired of waiting and tries to terminate the connection, I get this: 
fwdport   19309 user  5u  IPv4 296408  TCP *:2323 (LISTEN)
fwdport   19314 user  6u  IPv4 296409  TCP 10.1.10.20:2323->10.1.2.5:6
+0181 (CLOSE_WAIT)
fwdport   19314 user  7u  IPv4 296412  TCP 10.1.10.20:1044->10.1.1.2:t
+elnet (CLOSE_WAIT)
fwdport   19315 user  6u  IPv4 296409  TCP 10.1.10.20:2323->10.1.2.5:6
+0181 (CLOSE_WAIT)
fwdport   19315 user  7u  IPv4 296412  TCP 10.1.10.20:1044->10.1.1.2:t
+elnet (CLOSE_WAIT)

[download]
Hmmm... Perhaps the while isn't the problem. Maybe there's something weird in the IO::Socket::INET routines?
"Non sequitur. Your facts are un-coordinated." - Nomad

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Re: Re: Re: Help with socket connections
by jepri (Parson) on Nov 02, 2002 at 01:54 UTC
    IIRC recv doesn't block. Try setting up a test case using something like sysread, which should block, or fail when the socket closes. It will either work, or it will show you that the networking library is truely stuffed. You may be out of luck if the network library is stuffed, since perl tends to call straight through to the system, which means your system libraries are giving you trouble.

    You could probably write your routine using sysread and having it time out in .1 second, which would preserve interactivity.

    ____________________
    Jeremy
    I didn't believe in evil until I dated it.

[reply]
      Fixed it! With some help from a nice guy on another forum, but this was the solution: The recv call was getting stuck in a loop when the telnet session died unexpectedly - this might be a perl bug. The solution involved IO::Select, which works like a champ: 
      # this is the fork's parent, the master's child
      if ($kidpid) {
          set_state("$rs_info <-- $lc_info");
          my $buf = "";
          select($remote_server); $| = 1;
          my $s=IO::Select->new(); 
          $s->add($local_client);
          while (my @ready=$s->can_read())  {
            my $r=recv($local_client,$buf,1,0);
            warn "local recv - $!" unless(defined($r));
            last unless(length($buf));
            print $buf;
          };
          print STDOUT "Child Exiting: $lc_info --> $rs_info\n" if $de
+bug;
          log_info(0,$user,$lc_info,$rs_info); # Log disconnect
          kill('TERM', $kidpid);      # kill my twin cause we're done
          }
      # this is the fork's child, the master's grandchild
      else {
          set_state("$rs_info --> $lc_info");
          my $buf = "";
          select($local_client); $| = 1;
          my $s=IO::Select->new(); 
          $s->add($remote_server);
          while (my @ready=$s->can_read())  {
            my $r=recv($remote_server,$buf,1,0);
            warn "remote recv - $!" unless(defined($r));
            last unless(length($buf));
            print $buf;
          };
          print STDOUT "Grandchild Exiting: $lc_info <-- $rs_info\n" i
+f $debug;
          kill('TERM', getppid());    # kill my twin cause we're done
      }

      [download]
      Thanks everyone, for your help on this.
      "Non sequitur. Your facts are un-coordinated." - Nomad
[reply]
[d/l]

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