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Diff for /loncom/loncnew between versions 1.1 and 1.76

version 1.1, 2003/04/18 02:39:20 version 1.76, 2006/08/25 21:12:19
Line 1 Line 1
 #!/usr/bin/perl  #!/usr/bin/perl
   # The LearningOnline Network with CAPA
   # lonc maintains the connections to remote computers
 #  #
 # new lonc handles n requestors spread out bver m connections to londs.  # $Id$
   #
   # Copyright Michigan State University Board of Trustees
   #
   # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
   ## LON-CAPA is free software; you can redistribute it and/or modify
   # it under the terms of the GNU General Public License as published by
   # the Free Software Foundation; either version 2 of the License, or
   # (at your option) any later version.
   #
   # LON-CAPA is distributed in the hope that it will be useful,
   # but WITHOUT ANY WARRANTY; without even the implied warranty of
   # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   # GNU General Public License for more details.
   #
   # You should have received a copy of the GNU General Public License
   # along with LON-CAPA; if not, write to the Free Software
   # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   #
   # /home/httpd/html/adm/gpl.txt
   #
   # http://www.lon-capa.org/
   #
   #
   # new lonc handles n request out bver m connections to londs.
 # This module is based on the Event class.  # This module is based on the Event class.
 #   Development iterations:  #   Development iterations:
 #    - Setup basic event loop.   (done)  #    - Setup basic event loop.   (done)
 #    - Add timer dispatch.       (done)  #    - Add timer dispatch.       (done)
 #    - Add ability to accept lonc UNIX domain sockets.  (done)  #    - Add ability to accept lonc UNIX domain sockets.  (done)
 #    - Add ability to create/negotiate lond connections (done).  #    - Add ability to create/negotiate lond connections (done).
 #    - Add general logic for dispatching requests and timeouts.  #    - Add general logic for dispatching requests and timeouts. (done).
 #    - Add support for the lonc/lond requests.  #    - Add support for the lonc/lond requests.          (done).
 #    - Add logging/status monitoring.  #    - Add logging/status monitoring.                    (done)
 #    - Add Signal handling - HUP restarts. USR1 status report.  #    - Add Signal handling - HUP restarts. USR1 status report. (done)
 #    - Add Configuration file I/O  #    - Add Configuration file I/O                       (done).
 #    - Add Pending request processing on startup.  #    - Add management/status request interface.         (done)
 #    - Add management/status request interface.  #    - Add deferred request capability.                  (done)
   #    - Detect transmission timeouts.                     (done)
   #
   
   use strict;
 use lib "/home/httpd/lib/perl/";  use lib "/home/httpd/lib/perl/";
 use lib "/home/foxr/newloncapa/types";  
 use Event qw(:DEFAULT );  use Event qw(:DEFAULT );
 use POSIX qw(:signal_h);  use POSIX qw(:signal_h);
   use POSIX;
 use IO::Socket;  use IO::Socket;
 use IO::Socket::INET;  use IO::Socket::INET;
 use IO::Socket::UNIX;  use IO::Socket::UNIX;
   use IO::File;
   use IO::Handle;
 use Socket;  use Socket;
 use Crypt::IDEA;  use Crypt::IDEA;
 use LONCAPA::Queue;  use LONCAPA::Queue;
 use LONCAPA::Stack;  use LONCAPA::Stack;
 use LONCAPA::LondConnection;  use LONCAPA::LondConnection;
   use LONCAPA::LondTransaction;
 use LONCAPA::Configuration;  use LONCAPA::Configuration;
 use LONCAPA::HashIterator;  use LONCAPA::HashIterator;
   use Fcntl qw(:flock);
 print "Loncnew starting\n";  
   
 #  
 #   Disable all signals we might receive from outside for now.  
 #  
 $SIG{QUIT}  = IGNORE;  
 $SIG{HUP}   = IGNORE;  
 $SIG{USR1}  = IGNORE;  
 $SIG{INT}   = IGNORE;  
 $SIG{CHLD}  = IGNORE;  
 $SIG{__DIE__}  = IGNORE;  
   
   
 # Read the httpd configuration file to get perl variables  # Read the httpd configuration file to get perl variables
Line 53  my %perlvar    = %{$perlvarref}; Line 74  my %perlvar    = %{$perlvarref};
 #  parent and shared variables.  #  parent and shared variables.
   
 my %ChildHash; # by pid -> host.  my %ChildHash; # by pid -> host.
   my %HostToPid; # By host -> pid.
   my %HostHash; # by loncapaname -> IP.
   my %listening_to; # Socket->host table for who the parent
                                   # is listening to.
   my %parent_dispatchers;         # host-> listener watcher events. 
   
   my %parent_handlers; # Parent signal handlers...
   
 my $MaxConnectionCount = 5; # Will get from config later.  my $MaxConnectionCount = 10; # Will get from config later.
 my $ClientConnection = 0; # Uniquifier for client events.  my $ClientConnection = 0; # Uniquifier for client events.
   
 my $DebugLevel = 5;  my $DebugLevel = 0;
 my $IdleTimeout= 3600; # Wait an hour before pruning connections.  my $NextDebugLevel= 2; # So Sigint can toggle this.
   my $IdleTimeout= 600; # Wait 10 minutes before pruning connections.
   
   my $LogTransactions = 0; # When True, all transactions/replies get logged.
   my $executable      = $0; # Get the full path to me.
   
 #  #
 #  The variables below are only used by the child processes.  #  The variables below are only used by the child processes.
 #  #
 my $RemoteHost; # Name of host child is talking to.  my $RemoteHost; # Name of host child is talking to.
 my $UnixSocketDir= "/home/httpd/sockets";   my $UnixSocketDir= $perlvar{'lonSockDir'};
 my $IdleConnections = Stack->new(); # Set of idle connections  my $IdleConnections = Stack->new(); # Set of idle connections
 my %ActiveConnections; # Connections to the remote lond.  my %ActiveConnections; # Connections to the remote lond.
 my %ActiveTransactions; # Transactions in flight.  my %ActiveTransactions; # LondTransactions in flight.
 my %ActiveClients; # Serial numbers of active clients by socket.  my %ActiveClients; # Serial numbers of active clients by socket.
 my $WorkQueue       = Queue->new(); # Queue of pending transactions.  my $WorkQueue       = Queue->new(); # Queue of pending transactions.
 my $ClientQueue     = Queue->new(); # Queue of clients causing xactinos.  
 my $ConnectionCount = 0;  my $ConnectionCount = 0;
   my $IdleSeconds     = 0; # Number of seconds idle.
   my $Status          = ""; # Current status string.
   my $RecentLogEntry  = "";
   my $ConnectionRetries=5; # Number of connection retries allowed.
   my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
   my $LondVersion     = "unknown"; # Version of lond we talk with.
   my $KeyMode         = "";       # e.g. ssl, local, insecure from last connect.
   my $LondConnecting  = 0;       # True when a connection is being built.
   
   
   
   my $DieWhenIdle     = 1; # When true children die when trimmed -> 0.
   my $I_am_child      = 0; # True if this is the child process.
   
 #  #
   #   The hash below gives the HTML format for log messages
   #   given a severity.
   #    
   my %LogFormats;
   
   $LogFormats{"CRITICAL"} = "<font color='red'>CRITICAL: %s</font>";
   $LogFormats{"SUCCESS"}  = "<font color='green'>SUCCESS: %s</font>";
   $LogFormats{"INFO"}     = "<font color='yellow'>INFO: %s</font>";
   $LogFormats{"WARNING"}  = "<font color='blue'>WARNING: %s</font>";
   $LogFormats{"DEFAULT"}  = " %s ";
   
   
   #  UpdateStatus;
   #    Update the idle status display to show how many connections
   #    are left, retries and other stuff.
   #
   sub UpdateStatus {
       if ($ConnectionRetriesLeft > 0) {
    ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
      ." Retries remaining: ".$ConnectionRetriesLeft
      ." ($KeyMode)");
       } else {
    ShowStatus(GetServerHost()." >> DEAD <<");
       }
   }
   
   
   =pod
   
   =head2 LogPerm
   
   Makes an entry into the permanent log file.
   
   =cut
   
   sub LogPerm {
       my $message=shift;
       my $execdir=$perlvar{'lonDaemons'};
       my $now=time;
       my $local=localtime($now);
       my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
       print $fh "$now:$message:$local\n";
   }
   
   =pod
   
   =head2 Log
   
   Logs a message to the log file.
   Parameters:
   
   =item severity
   
   One of CRITICAL, WARNING, INFO, SUCCESS used to select the
   format string used to format the message.  if the severity is
   not a defined severity the Default format string is used.
   
   =item message
   
   The base message.  In addtion to the format string, the message
   will be appended to a string containing the name of our remote
   host and the time will be formatted into the message.
   
   =cut
   
   sub Log {
   
       my ($severity, $message) = @_;
   
       if(!$LogFormats{$severity}) {
    $severity = "DEFAULT";
       }
   
       my $format = $LogFormats{$severity};
       
       #  Put the window dressing in in front of the message format:
   
       my $now   = time;
       my $local = localtime($now);
       my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
       $finalformat = $finalformat.$format."\n";
   
       # open the file and put the result.
   
       my $execdir = $perlvar{'lonDaemons'};
       my $fh      = IO::File->new(">>$execdir/logs/lonc.log");
       my $msg = sprintf($finalformat, $message);
       $RecentLogEntry = $msg;
       print $fh $msg;
       
       
   }
   
   
 =pod  =pod
 =head 2 GetPeerName  
    Returns the name of the host that a socket object is connected  =head2 GetPeerName
    to.  
   Returns the name of the host that a socket object is connected to.
   
 =cut  =cut
   
 sub GetPeername {  sub GetPeername {
     my $connection = shift;  
     my $AdrFamily  = shift;  
       my ($connection, $AdrFamily) = @_;
   
     my $peer       = $connection->peername();      my $peer       = $connection->peername();
     my $peerport;      my $peerport;
     my $peerip;      my $peerip;
     if($AdrFamily == AF_INET) {      if($AdrFamily == AF_INET) {
  ($peerport, $peerip) = sockaddr_in($peer);   ($peerport, $peerip) = sockaddr_in($peer);
  my $peername    = gethostbyaddr($iaddr, $AdrFamily);   my $peername    = gethostbyaddr($peerip, $AdrFamily);
  return $peername;   return $peername;
     } elsif ($AdrFamily == AF_UNIX) {      } elsif ($AdrFamily == AF_UNIX) {
  my $peerfile;   my $peerfile;
Line 98  sub GetPeername { Line 238  sub GetPeername {
  return $peerfile;   return $peerfile;
     }      }
 }  }
 #----------------------------- Timer management ------------------------  
 =pod  =pod
   
 =head2 Debug  =head2 Debug
    Invoked to issue a debug message.  
   Invoked to issue a debug message.
   
 =cut  =cut
   
 sub Debug {  sub Debug {
     my $level   = shift;  
     my $message = shift;      my ($level, $message) = @_;
   
     if ($level <= $DebugLevel) {      if ($level <= $DebugLevel) {
  print $message." host = ".$RemoteHost."\n";   Log("INFO", "-Debug- $message host = $RemoteHost");
     }      }
 }  }
   
 sub SocketDump {  sub SocketDump {
     my $level = shift;  
     my $socket= shift;      my ($level, $socket) = @_;
   
     if($level <= $DebugLevel) {      if($level <= $DebugLevel) {
  $socket->Dump();   $socket->Dump(-1); # Ensure it will get dumped.
       }
   }
   
   =pod
   
   =head2 ShowStatus
   
    Place some text as our pid status.
    and as what we return in a SIGUSR1
   
   =cut
   
   sub ShowStatus {
       my $state = shift;
       my $now = time;
       my $local = localtime($now);
       $Status   = $local.": ".$state;
       $0='lonc: '.$state.' '.$local;
   }
   
   =pod
   
   =head2 SocketTimeout
   
       Called when an action on the socket times out.  The socket is 
      destroyed and any active transaction is failed.
   
   
   =cut
   
   sub SocketTimeout {
       my $Socket = shift;
       Log("WARNING", "A socket timeout was detected");
       Debug(5, " SocketTimeout called: ");
       $Socket->Dump(0);
       if(exists($ActiveTransactions{$Socket})) {
    FailTransaction($ActiveTransactions{$Socket});
     }      }
       KillSocket($Socket); # A transaction timeout also counts as
                                   # a connection failure:
       $ConnectionRetriesLeft--;
       if($ConnectionRetriesLeft <= 0) {
    Log("CRITICAL", "Host marked DEAD: ".GetServerHost());
    $LondConnecting = 0;
       }
   
 }  }
   #
   #   This function should be called by the child in all cases where it must
   #   exit.  If the child process is running with the DieWhenIdle turned on
   #   it must create a lock file for the AF_UNIX socket in order to prevent
   #   connection requests from lonnet in the time between process exit
   #   and the parent picking up the listen again.
   # Parameters:
   #     exit_code           - Exit status value, however see the next parameter.
   #     message             - If this optional parameter is supplied, the exit
   #                           is via a die with this message.
   #
   sub child_exit {
       my ($exit_code, $message) = @_;
   
       # Regardless of how we exit, we may need to do the lock thing:
   
       if($DieWhenIdle) {
    #
    #  Create a lock file since there will be a time window
    #  between our exit and the parent's picking up the listen
    #  during which no listens will be done on the
    #  lonnet client socket.
    #
    my $lock_file = GetLoncSocketPath().".lock";
    open(LOCK,">$lock_file");
    print LOCK "Contents not important";
    close(LOCK);
   
    exit(0);
       }
       #  Now figure out how we exit:
   
       if($message) {
    die $message;
       } else {
    exit($exit_code);
       }
   }
   #----------------------------- Timer management ------------------------
   
 =pod  =pod
   
 =head2 Tick  =head2 Tick
     Invoked  each timer tick.  
   Invoked  each timer tick.
   
 =cut  =cut
   
   
 sub Tick {  sub Tick {
       my ($Event)       = @_;
       my $clock_watcher = $Event->w;
   
     my $client;      my $client;
     Debug(6, "Tick");      UpdateStatus();
     Debug(6, "    Current connection count: ".$ConnectionCount);  
     foreach $client (keys %ActiveClients) {      # Is it time to prune connection count:
  Debug(7, "    Have client:  with id: ".$ActiveClients{$client});  
   
       if($IdleConnections->Count()  && 
          ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
    $IdleSeconds++;
    if($IdleSeconds > $IdleTimeout) { # Prune a connection...
       my $Socket = $IdleConnections->pop();
       KillSocket($Socket);
       $IdleSeconds = 0; # Otherwise all connections get trimmed to fast.
       UpdateStatus();
       if(($ConnectionCount == 0) && $DieWhenIdle) {
    &child_exit(0);
   
       }
    }
       } else {
    $IdleSeconds = 0; # Reset idle count if not idle.
       }
       #
       #  For each inflight transaction, tick down its timeout counter.
       #
   
       foreach my $item (keys %ActiveConnections) {
    my $State = $ActiveConnections{$item}->data->GetState();
    if ($State ne 'Idle') {
       Debug(5,"Ticking Socket $State $item");
       $ActiveConnections{$item}->data->Tick();
    }
       }
       # Do we have work in the queue, but no connections to service them?
       # If so, try to make some new connections to get things going again.
       #
       #   Note this code is dead now...
       #
       my $Requests = $WorkQueue->Count();
       if (($ConnectionCount == 0)  && ($Requests > 0) && (!$LondConnecting)) { 
    if ($ConnectionRetriesLeft > 0) {
       Debug(5,"Work but no connections, Make a new one");
       my $success;
       $success    = &MakeLondConnection;
       if($success == 0) { # All connections failed:
    Debug(5,"Work in queue failed to make any connectiouns\n");
    EmptyQueue(); # Fail pending transactions with con_lost.
    CloseAllLondConnections(); # Should all be closed but....
       }
    } else {
       $LondConnecting = 0;
       ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
       Debug(5,"Work in queue, but gave up on connections..flushing\n");
       EmptyQueue(); # Connections can't be established.
       CloseAllLondConnections(); # Should all already be closed but...
    }
          
       }
       if ($ConnectionCount == 0) {
    $KeyMode = ""; 
    $clock_watcher->cancel();
     }      }
       &UpdateStatus();
 }  }
   
 =pod  =pod
   
 =head2 SetupTimer  =head2 SetupTimer
    Sets up a 1 per sec recurring timer event.  The event handler is used to:  
   
 =item Trigger timeouts on communications along active sockets.  Sets up a 1 per sec recurring timer event.  The event handler is used to:
 =item Trigger disconnections of idle sockets.  
   =item
   
   Trigger timeouts on communications along active sockets.
   
   =item
   
   Trigger disconnections of idle sockets.
   
 =cut  =cut
   
 sub SetupTimer {  sub SetupTimer {
     Debug(6, "SetupTimer");      Debug(6, "SetupTimer");
     Event->timer(interval => 1, debug => 1, cb => \&Tick );      Event->timer(interval => 1, cb => \&Tick );
 }  }
   
 =pod  =pod
   
 =head2 ServerToIdle  =head2 ServerToIdle
    This function is called when a connection to the server is  
 ready for more work.   This function is called when a connection to the server is
    If there is work in the Work queue the top element is dequeued  ready for more work.
   
   If there is work in the Work queue the top element is dequeued
 and the connection will start to work on it.  If the work queue is  and the connection will start to work on it.  If the work queue is
 empty, the connection is pushed on the idle connection stack where  empty, the connection is pushed on the idle connection stack where
 it will either get another work unit, or alternatively, if it sits there  it will either get another work unit, or alternatively, if it sits there
 long enough, it will be shut down and released.  long enough, it will be shut down and released.
   
   
 =cut  =cut
   
 sub ServerToIdle {  sub ServerToIdle {
     my $Socket   = shift; # Get the socket.      my $Socket   = shift; # Get the socket.
       $KeyMode = $Socket->{AuthenticationMode};
       delete($ActiveTransactions{$Socket}); # Server has no transaction
   
     &Debug(6, "Server to idle");      &Debug(5, "Server to idle");
   
     #  If there's work to do, start the transaction:      #  If there's work to do, start the transaction:
   
     $reqdata = $WorkQueue->dequeue();      my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
     Debug(9, "Queue gave request data: ".$reqdata);      if ($reqdata ne undef)  {
     unless($reqdata eq undef)  {   Debug(5, "Queue gave request data: ".$reqdata->getRequest());
  my $unixSocket = $ClientQueue->dequeue();   &StartRequest($Socket,  $reqdata);
  &Debug(6, "Starting new work request");  
  &Debug(7, "Request: ".$reqdata);  
   
  &StartRequest($Socket, $unixSocket, $reqdata);  
     } else {      } else {
   
     #  There's no work waiting, so push the server to idle list.      #  There's no work waiting, so push the server to idle list.
  &Debug(8, "No new work requests, server connection going idle");   &Debug(5, "No new work requests, server connection going idle");
  delete($ActiveTransactions{$Socket});  
  $IdleConnections->push($Socket);   $IdleConnections->push($Socket);
     }      }
 }  }
   
 =pod  =pod
   
 =head2 ClientWritable  =head2 ClientWritable
   Event callback for when a client socket is writable.  
   This callback is established when a transaction reponse is  Event callback for when a client socket is writable.
   avaiable from lond.  The response is forwarded to the unix socket  
   as it becomes writable in this sub.  This callback is established when a transaction reponse is
   avaiable from lond.  The response is forwarded to the unix socket
   as it becomes writable in this sub.
   
 Parameters:  Parameters:
   
 =item Event - The event that has been triggered. Event->w->data is  =item Event
               the data and Event->w->fd is the socket to write.  
   The event that has been triggered. Event->w->data is
   the data and Event->w->fd is the socket to write.
   
 =cut  =cut
   
 sub ClientWritable {  sub ClientWritable {
     my $Event    = shift;      my $Event    = shift;
     my $Watcher  = $Event->w;      my $Watcher  = $Event->w;
Line 204  sub ClientWritable { Line 514  sub ClientWritable {
     &Debug(6, "ClientWritable writing".$Data);      &Debug(6, "ClientWritable writing".$Data);
     &Debug(9, "Socket is: ".$Socket);      &Debug(9, "Socket is: ".$Socket);
   
     my $result = $Socket->send($Data, 0);      if($Socket->connected) {
    my $result = $Socket->send($Data, 0);
     # $result undefined: the write failed.  
     # otherwise $result is the number of bytes written.   # $result undefined: the write failed.
     # Remove that preceding string from the data.   # otherwise $result is the number of bytes written.
     # If the resulting data is empty, destroy the watcher   # Remove that preceding string from the data.
     # and set up a read event handler to accept the next   # If the resulting data is empty, destroy the watcher
     # request.   # and set up a read event handler to accept the next
    # request.
     &Debug(9,"Send result is ".$result." Defined: ".defined($result));  
     if(defined($result)) {   &Debug(9,"Send result is ".$result." Defined: ".defined($result));
  &Debug(9, "send result was defined");   if($result ne undef) {
  if($result == length($Data)) { # Entire string sent.      &Debug(9, "send result was defined");
     &Debug(9, "ClientWritable data all written");      if($result == length($Data)) { # Entire string sent.
     $Watcher->cancel();   &Debug(9, "ClientWritable data all written");
     #   $Watcher->cancel();
     #  Set up to read next request from socket:   #
    #  Set up to read next request from socket:
   
    my $descr     = sprintf("Connection to lonc client %d",
    $ActiveClients{$Socket});
    Event->io(cb    => \&ClientRequest,
     poll  => 'r',
     desc  => $descr,
     data  => "",
     fd    => $Socket);
   
       } else { # Partial string sent.
    $Watcher->data(substr($Data, $result));
    if($result == 0) {    # client hung up on us!!
       # Log("INFO", "lonc pipe client hung up on us!");
       $Watcher->cancel;
       $Socket->shutdown(2);
       $Socket->close();
    }
       }
       
    } else { # Error of some sort...
       
       # Some errnos are possible:
       my $errno = $!;
       if($errno == POSIX::EWOULDBLOCK   ||
          $errno == POSIX::EAGAIN        ||
          $errno == POSIX::EINTR) {
    # No action taken?
       } else { # Unanticipated errno.
    &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
    $Watcher->cancel; # Stop the watcher.
    $Socket->shutdown(2); # Kill connection
    $Socket->close(); # Close the socket.
       }
           
     my $descr     = sprintf("Connection to lonc client %d",  
     $ActiveClients{$Socket});  
     Event->io(cb    => \&ClientRequest,  
       poll  => 'r',  
       desc  => $descr,  
       data  => "",  
       fd    => $Socket);  
   
  } else { # Partial string sent.  
     $Watcher->data(substr($Data, $result));  
  }  
   
     } else { # Error of some sort...  
   
  # Some errnos are possible:  
  my $errno = $!;  
  if($errno == POSIX::EWOULDBLOCK   ||  
    $errno == POSIX::EAGAIN        ||  
    $errno == POSIX::EINTR) {  
     # No action taken?  
  } else { # Unanticipated errno.  
     &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);  
     $Watcher->cancel; # Stop the watcher.  
     $Socket->shutdown(2); # Kill connection  
     $Socket->close(); # Close the socket.  
  }   }
       } else {
    $Watcher->cancel(); # A delayed request...just cancel.
     }      }
 }  }
   
 =pod  =pod
   
 =head2 CompleteTransaction  =head2 CompleteTransaction
   Called when the reply data has been received for a lond   
   Called when the reply data has been received for a lond 
 transaction.   The reply data must now be sent to the  transaction.   The reply data must now be sent to the
 ultimate client on the other end of the Unix socket.  This is  ultimate client on the other end of the Unix socket.  This is
 done by setting up a writable event for the socket with the  done by setting up a writable event for the socket with the
 data the reply data.  data the reply data.
   
 Parameters:  Parameters:
 =item Socket - Socket on which the lond transaction occured.  This  
       is a LondConnection. The data received is in the   =item Socket
  TransactionReply member.  
 =item Client - Unix domain socket open on the ultimate client.  Socket on which the lond transaction occured.  This is a
   LondConnection. The data received is in the TransactionReply member.
   
   =item Transaction
   
   The transaction that is being completed.
   
 =cut  =cut
   
 sub CompleteTransaction {  sub CompleteTransaction {
     &Debug(6,"Complete transaction");      &Debug(5,"Complete transaction");
     my $Socket = shift;  
     my $Client = shift;      my ($Socket, $Transaction) = @_;
   
       if (!$Transaction->isDeferred()) { # Normal transaction
    my $data   = $Socket->GetReply(); # Data to send.
    if($LogTransactions) {
       Log("SUCCESS", "Reply from lond: '$data'");
    }
    StartClientReply($Transaction, $data);
       } else { # Delete deferred transaction file.
    Log("SUCCESS", "A delayed transaction was completed");
    LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
    unlink $Transaction->getFile();
       }
   }
   
   =pod
   
   =head1 StartClientReply
   
      Initiates a reply to a client where the reply data is a parameter.
   
   =head2  parameters:
   
   =item Transaction
   
       The transaction for which we are responding to the client.
   
   =item data
   
       The data to send to apached client.
   
   =cut
   
   sub StartClientReply {
   
     my $data   = $Socket->GetReply(); # Data to send.      my ($Transaction, $data) = @_;
   
       my $Client   = $Transaction->getClient();
   
     &Debug(8," Reply was: ".$data);      &Debug(8," Reply was: ".$data);
     my $Serial         = $ActiveClients{$Client};      my $Serial         = $ActiveClients{$Client};
Line 284  sub CompleteTransaction { Line 648  sub CompleteTransaction {
       data     => $data);        data     => $data);
 }  }
   
   =pod
   
   =head2 FailTransaction
   
     Finishes a transaction with failure because the associated lond socket
     disconnected.  There are two possibilities:
     - The transaction is deferred: in which case we just quietly
       delete the transaction since there is no client connection.
     - The transaction is 'live' in which case we initiate the sending
       of "con_lost" to the client.
   
   Deleting the transaction means killing it from the %ActiveTransactions hash.
   
   Parameters:
   
   =item client  
    
      The LondTransaction we are failing.
    
   
   =cut
   
   sub FailTransaction {
       my $transaction = shift;
       
       #  If the socket is dead, that's already logged.
   
       if ($ConnectionRetriesLeft > 0) {
    Log("WARNING", "Failing transaction "
       .$transaction->getLoggableRequest());
       }
       Debug(1, "Failing transaction: ".$transaction->getLoggableRequest());
       if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
    my $client  = $transaction->getClient();
    Debug(1," Replying con_lost to ".$transaction->getRequest());
    StartClientReply($transaction, "con_lost\n");
       }
   
   }
   
   =pod
   
   =head1  EmptyQueue
   
     Fails all items in the work queue with con_lost.
     Note that each item in the work queue is a transaction.
   
   =cut
   
   sub EmptyQueue {
       $ConnectionRetriesLeft--; # Counts as connection failure too.
       while($WorkQueue->Count()) {
    my $request = $WorkQueue->dequeue(); # This is a transaction
    FailTransaction($request);
       }
   }
   
   =pod
   
   =head2 CloseAllLondConnections
   
   Close all connections open on lond prior to exit e.g.
   
   =cut
   
   sub CloseAllLondConnections {
       foreach my $Socket (keys %ActiveConnections) {
         if(exists($ActiveTransactions{$Socket})) {
    FailTransaction($ActiveTransactions{$Socket});
         }
         KillSocket($Socket);
       }
   }
   
   =pod
   
   =head2 KillSocket
    
   Destroys a socket.  This function can be called either when a socket
   has died of 'natural' causes or because a socket needs to be pruned due to
   idleness.  If the socket has died naturally, if there are no longer any 
   live connections a new connection is created (in case there are transactions
   in the queue).  If the socket has been pruned, it is never re-created.
   
   Parameters:
   
   =item Socket
    
     The socket to kill off.
   
   =item Restart
   
   nonzero if we are allowed to create a new connection.
   
   =cut
   
   sub KillSocket {
       my $Socket = shift;
   
       Log("WARNING", "Shutting down a socket");
       $Socket->Shutdown();
   
       #  If the socket came from the active connection set,
       #  delete its transaction... note that FailTransaction should
       #  already have been called!!!
       #  otherwise it came from the idle set.
       #  
       
       if(exists($ActiveTransactions{$Socket})) {
    delete ($ActiveTransactions{$Socket});
       }
       if(exists($ActiveConnections{$Socket})) {
    delete($ActiveConnections{$Socket});
    $ConnectionCount--;
    if ($ConnectionCount < 0) { $ConnectionCount = 0; }
       }
       #  If the connection count has gone to zero and there is work in the
       #  work queue, the work all gets failed with con_lost.
       #
       if($ConnectionCount == 0) {
    EmptyQueue();
    CloseAllLondConnections; # Should all already be closed but...
       }
   }
   
 =pod  =pod
   
 =head2 LondReadable  =head2 LondReadable
   
 This function is called whenever a lond connection  This function is called whenever a lond connection
 is readable.  The action is state dependent:  is readable.  The action is state dependent:
   
 =head3 State = Initialized  =head3 State=Initialized
     We''re waiting for the challenge, this is a no-op until the  
   We''re waiting for the challenge, this is a no-op until the
 state changes.  state changes.
   
 =head3 State=Challenged   =head3 State=Challenged 
     The challenge has arrived we need to transition to Writable.  
   The challenge has arrived we need to transition to Writable.
 The connection must echo the challenge back.  The connection must echo the challenge back.
   
 =head3 State=ChallengeReplied  =head3 State=ChallengeReplied
     The challenge has been replied to.  The we are receiveing the   
   The challenge has been replied to.  The we are receiveing the 
 'ok' from the partner.  'ok' from the partner.
   
   =head3  State=ReadingVersionString
   
   We have requested the lond version and are reading the
   version back.  Upon completion, we'll store the version away
   for future use(?).
   
   =head3 State=HostSet
   
   We have selected the domain name of our peer (multhomed hosts)
   and are getting the reply (presumably ok) back.
   
 =head3 State=RequestingKey  =head3 State=RequestingKey
     The ok has been received and we need to send the request for  
   The ok has been received and we need to send the request for
 an encryption key.  Transition to writable for that.  an encryption key.  Transition to writable for that.
   
 =head3 State=ReceivingKey  =head3 State=ReceivingKey
     The the key has been requested, now we are reading the new key.  
   The the key has been requested, now we are reading the new key.
   
 =head3 State=Idle   =head3 State=Idle 
     The encryption key has been negotiated or we have finished   
   The encryption key has been negotiated or we have finished 
 reading data from the a transaction.   If the callback data has  reading data from the a transaction.   If the callback data has
 a client as well as the socket iformation, then we are   a client as well as the socket iformation, then we are 
 doing a transaction and the data received is relayed to the client  doing a transaction and the data received is relayed to the client
 before the socket is put on the idle list.  before the socket is put on the idle list.
   
 =head3 State=SendingRequest  =head3 State=SendingRequest
     I do not think this state can be received here, but if it is,  
   I do not think this state can be received here, but if it is,
 the appropriate thing to do is to transition to writable, and send  the appropriate thing to do is to transition to writable, and send
 the request.  the request.
   
 =head3 State=ReceivingReply  =head3 State=ReceivingReply
     We finished sending the request to the server and now transition  
   We finished sending the request to the server and now transition
 to readable to receive the reply.   to readable to receive the reply. 
   
 The parameter to this function are:  The parameter to this function are:
   
 The event. Implicit in this is the watcher and its data.  The data   The event. Implicit in this is the watcher and its data.  The data 
 contains at least the lond connection object and, if a   contains at least the lond connection object and, if a 
 transaction is in progress, the socket attached to the local client.  transaction is in progress, the socket attached to the local client.
   
   
 =cut  =cut
   
 sub LondReadable {  sub LondReadable {
   
     my $Event      = shift;      my $Event      = shift;
     my $Watcher    = $Event->w;      my $Watcher    = $Event->w;
     my $Socket     = $Watcher->data;      my $Socket     = $Watcher->data;
     my $client     = undef;      my $client     = undef;
   
       &Debug(6,"LondReadable called state = ".$Socket->GetState());
   
   
     my $State = $Socket->GetState(); # All action depends on the state.      my $State = $Socket->GetState(); # All action depends on the state.
   
     &Debug(6,"LondReadable called state = ".$State);  
     SocketDump(6, $Socket);      SocketDump(6, $Socket);
       my $status = $Socket->Readable();
   
       &Debug(2, "Socket->Readable returned: $status");
   
     if($Socket->Readable() != 0) {      if($status != 0) {
  # bad return from socket read.   # bad return from socket read. Currently this means that
    # The socket has become disconnected. We fail the transaction.
   
    Log("WARNING",
       "Lond connection lost.");
    if(exists($ActiveTransactions{$Socket})) {
       FailTransaction($ActiveTransactions{$Socket});
    } else {
       #  Socket is connecting and failed... need to mark
       #  no longer connecting.
      
       $LondConnecting = 0;
    }
    $Watcher->cancel();
    KillSocket($Socket);
    $ConnectionRetriesLeft--;       # Counts as connection failure
    return;
     }      }
     SocketDump(6,$Socket);      SocketDump(6,$Socket);
   
     $State = $Socket->GetState(); # Update in case of transition.      $State = $Socket->GetState(); # Update in case of transition.
     &Debug(6, "After read, state is ".$State);      &Debug(6, "After read, state is ".$State);
   
    if($State eq "Initialized") {      if($State eq "Initialized") {
   
   
     } elsif ($State eq "ChallengeReceived") {      } elsif ($State eq "ChallengeReceived") {
  #  The challenge must be echoed back;  The state machine   #  The challenge must be echoed back;  The state machine
  # in the connection takes care of setting that up.  Just   # in the connection takes care of setting that up.  Just
  # need to transition to writable:   # need to transition to writable:
   
  $Watcher->poll("w");  
  $Watcher->cb(\&LondWritable);   $Watcher->cb(\&LondWritable);
    $Watcher->poll("w");
   
     } elsif ($State eq "ChallengeReplied") {      } elsif ($State eq "ChallengeReplied") {
   
       } elsif ($State eq "RequestingVersion") {
    # Need to ask for the version... that is writiability:
   
    $Watcher->cb(\&LondWritable);
    $Watcher->poll("w");
   
       } elsif ($State eq "ReadingVersionString") {
    # Read the rest of the version string... 
       } elsif ($State eq "SetHost") {
    # Need to request the actual domain get set...
   
    $Watcher->cb(\&LondWritable);
    $Watcher->poll("w");
       } elsif ($State eq "HostSet") {
    # Reading the 'ok' from the peer.
   
     } elsif ($State eq "RequestingKey") {      } elsif ($State eq "RequestingKey") {
  #  The ok was received.  Now we need to request the key   #  The ok was received.  Now we need to request the key
  #  That requires us to be writable:   #  That requires us to be writable:
   
  $Watcher->poll("w");  
  $Watcher->cb(\&LondWritable);   $Watcher->cb(\&LondWritable);
    $Watcher->poll("w");
   
     } elsif ($State eq "ReceivingKey") {      } elsif ($State eq "ReceivingKey") {
   
     } elsif ($State eq "Idle") {      } elsif ($State eq "Idle") {
      
    # This is as good a spot as any to get the peer version
    # string:
      
    if($LondVersion eq "unknown") {
       $LondVersion = $Socket->PeerVersion();
       Log("INFO", "Connected to lond version: $LondVersion");
    }
  # If necessary, complete a transaction and then go into the   # If necessary, complete a transaction and then go into the
  # idle queue.   # idle queue.
    #  Note that a trasition to idle indicates a live lond
    # on the other end so reset the connection retries.
    #
    $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
    $Watcher->cancel();
  if(exists($ActiveTransactions{$Socket})) {   if(exists($ActiveTransactions{$Socket})) {
     Debug(8,"Completing transaction!!");      Debug(5,"Completing transaction!!");
     CompleteTransaction($Socket,       CompleteTransaction($Socket, 
  $ActiveTransactions{$Socket});   $ActiveTransactions{$Socket});
    } else {
       Log("SUCCESS", "Connection ".$ConnectionCount." to "
    .$RemoteHost." now ready for action");
  }   }
  $Watcher->cancel();  
  ServerToIdle($Socket); # Next work unit or idle.   ServerToIdle($Socket); # Next work unit or idle.
   
    #
    $LondConnecting = 0; # Best spot I can think of for this.
    # 
   
     } elsif ($State eq "SendingRequest") {      } elsif ($State eq "SendingRequest") {
  #  We need to be writable for this and probably don't belong   #  We need to be writable for this and probably don't belong
  #  here inthe first place.   #  here inthe first place.
   
  Deubg(6, "SendingRequest state encountered in readable");   Debug(6, "SendingRequest state encountered in readable");
  $Watcher->poll("w");   $Watcher->poll("w");
  $Watcher->cb(\&LondWritable);   $Watcher->cb(\&LondWritable);
   
Line 391  sub LondReadable { Line 963  sub LondReadable {
   
   
     } else {      } else {
  # Invalid state.   # Invalid state.
  Debug(4, "Invalid state in LondReadable");   Debug(4, "Invalid state in LondReadable");
     }      }
 }  }
   
 =pod  =pod
   
 =head2 LondWritable  =head2 LondWritable
   
 This function is called whenever a lond connection  This function is called whenever a lond connection
 becomes writable while there is a writeable monitoring  becomes writable while there is a writeable monitoring
 event.  The action taken is very state dependent:  event.  The action taken is very state dependent:
   
 =head3 State = Connected   =head3 State = Connected 
   The connection is in the process of sending the  
   'init' hailing to the lond on the remote end.  The connection is in the process of sending the 'init' hailing to the
    The connection object''s Writable member is called.  lond on the remote end.  The connection object''s Writable member is
    On error, ConnectionError is called to destroy  called.  On error, ConnectionError is called to destroy the connection
    the connection and remove it from the ActiveConnections  and remove it from the ActiveConnections hash
    hash  
 =head3 Initialized  =head3 Initialized
    'init' has been sent, writability monitoring is   
     removed and readability monitoring is started  'init' has been sent, writability monitoring is removed and
     with LondReadable as the callback.  readability monitoring is started with LondReadable as the callback.
   
 =head3 ChallengeReceived  =head3 ChallengeReceived
     The connection has received the who are you   
    challenge from the remote system, and is in the  The connection has received the who are you challenge from the remote
     process of sending the challenge response.   system, and is in the process of sending the challenge
     Writable is called.  response. Writable is called.
   
 =head3 ChallengeReplied  =head3 ChallengeReplied
     The connection has replied to the initial challenge  
     The we switch to monitoring readability looking  The connection has replied to the initial challenge The we switch to
     for the server to reply with 'ok'.  monitoring readability looking for the server to reply with 'ok'.
   
 =head3 RequestingKey  =head3 RequestingKey
     The connection is in the process of requesting its  
     encryption key.  Writable is called.  The connection is in the process of requesting its encryption key.
   Writable is called.
   
 =head3 ReceivingKey  =head3 ReceivingKey
     The connection has sent the request for a key.  
     Switch to readability monitoring to accept the key  The connection has sent the request for a key.  Switch to readability
   monitoring to accept the key
   
 =head3 SendingRequest  =head3 SendingRequest
     The connection is in the process of sending a  
     request to the server.  This request is part of  The connection is in the process of sending a request to the server.
     a client transaction.  All the states until now  This request is part of a client transaction.  All the states until
     represent the client setup protocol. Writable  now represent the client setup protocol. Writable is called.
     is called.  
 =head3 ReceivingReply  =head3 ReceivingReply
     The connection has sent a request.  Now it must  
     receive a reply.  Readability monitoring is  
     requested.  
   
  This function is an event handler and therefore receives as  The connection has sent a request.  Now it must receive a reply.
   Readability monitoring is requested.
   
   This function is an event handler and therefore receives as
 a parameter the event that has fired.  The data for the watcher  a parameter the event that has fired.  The data for the watcher
 of this event is a reference to a list of one or two elements,  of this event is a reference to a list of one or two elements,
 depending on state. The first (and possibly only) element is the  depending on state. The first (and possibly only) element is the
Line 445  socket.  The second (present only if a r Line 1028  socket.  The second (present only if a r
 is the socket on which to return a reply to the caller.  is the socket on which to return a reply to the caller.
   
 =cut  =cut
   
 sub LondWritable {  sub LondWritable {
     my $Event   = shift;      my $Event   = shift;
     my $Watcher = $Event->w;      my $Watcher = $Event->w;
     my @data    = $Watcher->data;      my $Socket  = $Watcher->data;
     Debug(6,"LondWritable State = ".$State." data has ".@data." elts.\n");      my $State   = $Socket->GetState();
   
     my $Socket  = $data[0]; # I know there's at least a socket.      Debug(6,"LondWritable State = ".$State."\n");
   
    
     #  Figure out what to do depending on the state of the socket:      #  Figure out what to do depending on the state of the socket:
           
   
     my $State   = $Socket->GetState();  
   
   
     SocketDump(6,$Socket);      SocketDump(6,$Socket);
   
       #  If the socket is writable, we must always write.
       # Only by writing will we undergo state transitions.
       # Old logic wrote in state specific code below, however
       # That forces us at least through another invocation of
       # this function after writability is possible again.
       # This logic also factors out common code for handling
       # write failures... in all cases, write failures 
       # Kill the socket.
       #  This logic makes the branches of the >big< if below
       # so that the writing states are actually NO-OPs.
   
       if ($Socket->Writable() != 0) {
    #  The write resulted in an error.
    # We'll treat this as if the socket got disconnected:
    Log("WARNING", "Connection to ".$RemoteHost.
       " has been disconnected");
    if(exists($ActiveTransactions{$Socket})) {
       FailTransaction($ActiveTransactions{$Socket});
    } else {
       #  In the process of conneting, so need to turn that off.
       
       $LondConnecting = 0;
    }
    $Watcher->cancel();
    KillSocket($Socket);
    return;
       }
   
   
   
     if      ($State eq "Connected")         {      if      ($State eq "Connected")         {
  #  "init" is being sent...  
   
  if ($Socket->Writable() != 0) {   #  "init" is being sent...
     #  The write resulted in an error.   
  }  
   
     } elsif ($State eq "Initialized")       {      } elsif ($State eq "Initialized")       {
   
  # Now that init was sent, we switch    # Now that init was sent, we switch 
  # to watching for readability:   # to watching for readability:
   
  $Watcher->poll("r");  
  $Watcher->cb(\&LondReadable);   $Watcher->cb(\&LondReadable);
    $Watcher->poll("r");
   
     } elsif ($State eq "ChallengeReceived") {      } elsif ($State eq "ChallengeReceived") {
  # We received the challenge, now we    # We received the challenge, now we 
  # are echoing it back. This is a no-op,   # are echoing it back. This is a no-op,
  # we're waiting for the state to change   # we're waiting for the state to change
   
  if($Socket->Writable() != 0) {  
     # Write of the next chunk resulted in an error.  
  }  
   
     } elsif ($State eq "ChallengeReplied")  {      } elsif ($State eq "ChallengeReplied")  {
  # The echo was sent back, so we switch   # The echo was sent back, so we switch
  # to watching readability.   # to watching readability.
   
    $Watcher->cb(\&LondReadable);
    $Watcher->poll("r");
       } elsif ($State eq "RequestingVersion") {
    # Sending the peer a version request...
   
       } elsif ($State eq "ReadingVersionString") {
    # Transition to read since we have sent the
    # version command and now just need to read the
    # version string from the peer:
         
    $Watcher->cb(\&LondReadable);
  $Watcher->poll("r");   $Watcher->poll("r");
         
       } elsif ($State eq "SetHost") {
    #  Setting the remote domain...
   
       } elsif ($State eq "HostSet") {
    # Back to readable to get the ok.
         
  $Watcher->cb(\&LondReadable);   $Watcher->cb(\&LondReadable);
    $Watcher->poll("r");
         
   
     } elsif ($State eq "RequestingKey")     {      } elsif ($State eq "RequestingKey")     {
  # At this time we're requesting the key.   # At this time we're requesting the key.
  # again, this is essentially a no-op.   # again, this is essentially a no-op.
  # we'll write the next chunk until the  
  # state changes.  
   
  if($Socket->Writable() != 0) {  
     # Write resulted in an error.  
  }  
   
     } elsif ($State eq "ReceivingKey")      {      } elsif ($State eq "ReceivingKey")      {
  # Now we need to wait for the key   # Now we need to wait for the key
  # to come back from the peer:   # to come back from the peer:
   
  $Watcher->poll("r");  
  $Watcher->cb(\&LondReadable);   $Watcher->cb(\&LondReadable);
    $Watcher->poll("r");
   
     } elsif ($State eq "SendingRequest")    {      } elsif ($State eq "SendingRequest")    {
    
  # At this time we are sending a request to the   # At this time we are sending a request to the
  # peer... write the next chunk:   # peer... write the next chunk:
   
  if($Socket->Writable() != 0) {  
     # Write resulted in an error.  
   
  }  
   
     } elsif ($State eq "ReceivingReply")    {      } elsif ($State eq "ReceivingReply")    {
  # The send has completed.  Wait for the   # The send has completed.  Wait for the
  # data to come in for a reply.   # data to come in for a reply.
  Debug(8,"Writable sent request/receiving reply");   Debug(8,"Writable sent request/receiving reply");
  $Watcher->poll("r");  
  $Watcher->cb(\&LondReadable);   $Watcher->cb(\&LondReadable);
    $Watcher->poll("r");
   
     } else {      } else {
  #  Control only passes here on an error:    #  Control only passes here on an error: 
Line 535  sub LondWritable { Line 1153  sub LondWritable {
     }      }
           
 }  }
   =pod
       
   =cut
   
   sub QueueDelayed {
       Debug(3,"QueueDelayed called");
   
       my $path = "$perlvar{'lonSockDir'}/delayed";
   
       Debug(4, "Delayed path: ".$path);
       opendir(DIRHANDLE, $path);
   
       my @all_host_ids;
       my $host_iterator =   &LondConnection::GetHostIterator();
       while (!$host_iterator->end()) {
    my ($host_id,$host_name) = @{$host_iterator->get()}[0,3];
    if ($host_name eq $RemoteHost) {
       push(@all_host_ids, $host_id);
    }
    $host_iterator->next();
       }
       my $host_id_re = '(?:'.join('|',@all_host_ids).')';
       my @alldelayed = grep(/\.$host_id_re$/, readdir(DIRHANDLE));
       closedir(DIRHANDLE);
       foreach my $dfname (sort(@alldelayed)) {
    my $reqfile = "$path/$dfname";
    my ($host_id) = ($dfname =~ /\.([^.]*)$/);
    Debug(4, "queueing ".$reqfile." for $host_id");
    my $Handle = IO::File->new($reqfile);
    my $cmd    = <$Handle>;
    chomp $cmd; # There may or may not be a newline...
    $cmd = $cmd."\n"; # now for sure there's exactly one newline.
    my $Transaction = LondTransaction->new("sethost:$host_id:$cmd");
    $Transaction->SetDeferred($reqfile);
    QueueTransaction($Transaction);
       }
       
   }
   
 =pod  =pod
   
 =head2 MakeLondConnection  =head2 MakeLondConnection
     Create a new lond connection object, and start it towards  
     its initial idleness.  Once idle, it becomes elligible to  Create a new lond connection object, and start it towards its initial
     receive transactions from the work queue.  If the work queue  idleness.  Once idle, it becomes elligible to receive transactions
     is not empty when the connection is completed and becomes idle,  from the work queue.  If the work queue is not empty when the
     it will dequeue an entry and start off on it.  connection is completed and becomes idle, it will dequeue an entry and
   start off on it.
   
 =cut  =cut
   
 sub MakeLondConnection {       sub MakeLondConnection {     
     Debug(4,"MakeLondConnection to ".GetServerHost()." on port "      Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
   .GetServerPort());    .GetServerPort());
Line 551  sub MakeLondConnection { Line 1211  sub MakeLondConnection {
     my $Connection = LondConnection->new(&GetServerHost(),      my $Connection = LondConnection->new(&GetServerHost(),
  &GetServerPort());   &GetServerPort());
   
     if($Connection == undef) { # Needs to be more robust later.      if($Connection eq undef) { # Needs to be more robust later.
  die "Failed to make a connection!!".$!."\n";   Log("CRITICAL","Failed to make a connection with lond.");
    $ConnectionRetriesLeft--;
    return 0; # Failure.
       }  else {
   
    # The connection needs to have writability 
    # monitored in order to send the init sequence
    # that starts the whole authentication/key
    # exchange underway.
    #
    my $Socket = $Connection->GetSocket();
    if($Socket eq undef) {
       &child_exit(-1, "did not get a socket from the connection");
    } else {
       &Debug(9,"MakeLondConnection got socket: ".$Socket);
    }
   
     }    $Connection->SetTimeoutCallback(\&SocketTimeout);
     # The connection needs to have writability   
     # monitored in order to send the init sequence  
     # that starts the whole authentication/key  
     # exchange underway.  
     #  
     my $Socket = $Connection->GetSocket();  
     if($Socket == undef) {  
  die "did not get a socket from the connection";  
     } else {  
  &Debug(9,"MakeLondConnection got socket: ".$Socket);  
     }  
   
       
     $event = Event->io(fd       => $Socket,  
        poll     => 'w',  
        cb       => \&LondWritable,  
        data     => ($Connection, undef),  
        desc => 'Connection to lond server');  
     $ActiveConnections{$Lond} = $event;  
   
     $ConnectionCount++;   my $event = Event->io(fd       => $Socket,
         poll     => 'w',
      cb       => \&LondWritable,
      data     => $Connection,
      desc => 'Connection to lond server');
    $ActiveConnections{$Connection} = $event;
    if ($ConnectionCount == 0) {
       &SetupTimer; # Need to handle timeouts with connections...
    }
    $ConnectionCount++;
    Debug(4, "Connection count = ".$ConnectionCount);
    if($ConnectionCount == 1) { # First Connection:
       QueueDelayed;
    }
    Log("SUCESS", "Created connection ".$ConnectionCount
       ." to host ".GetServerHost());
    $LondConnecting = 1; # Connection in progress.
    return 1; # Return success.
       }
           
 }  }
   
 =pod  =pod
   
 =head2 StartRequest  =head2 StartRequest
    Starts a lond request going on a specified lond connection.  
     parameters are:  Starts a lond request going on a specified lond connection.
 =item $Lond - Connection to the lond that will send the transaction  parameters are:
     and receive the reply.  
 =item $Client - Connection to the client that is making this request  =item $Lond
     We got the request from this socket, and when the request has  
     been relayed to lond and we get a reply back from lond it will  Connection to the lond that will send the transaction and receive the
     get sent to this socket.  reply.
 =item $Request - The text of the request to send.  
   =item $Client
   
   Connection to the client that is making this request We got the
   request from this socket, and when the request has been relayed to
   lond and we get a reply back from lond it will get sent to this
   socket.
   
   =item $Request
   
   The text of the request to send.
   
 =cut  =cut
   
 sub StartRequest {  sub StartRequest {
     my $Lond     = shift;  
     my $Client   = shift;      my ($Lond, $Request) = @_;
     my $Request  = shift;  
           
     Debug(6, "StartRequest: ".$Request);      Debug(6, "StartRequest: ".$Request->getRequest());
   
     my $Socket = $Lond->GetSocket();      my $Socket = $Lond->GetSocket();
           
     $ActiveTransactions{$Lond} = $Client; # Socket to relay to client.      $Request->Activate($Lond);
       $ActiveTransactions{$Lond} = $Request;
   
     $Lond->InitiateTransaction($Request);      $Lond->InitiateTransaction($Request->getRequest());
     $event = Event->io(fd      => $Lond->GetSocket(),      my $event = Event->io(fd      => $Socket,
        poll    => "w",         poll    => "w",
        cb      => \&LondWritable,         cb      => \&LondWritable,
        data    => $Lond,         data    => $Lond,
Line 614  sub StartRequest { Line 1300  sub StartRequest {
 }  }
   
 =pod  =pod
   
 =head2 QueueTransaction  =head2 QueueTransaction
     - If there is an idle lond connection, it is put to   
     work doing this transaction.  Otherwise, the transaction is  If there is an idle lond connection, it is put to work doing this
     placed in the work queue.  If placed in the work queue and the  transaction.  Otherwise, the transaction is placed in the work queue.
     maximum number of connections has not yet been created, a new  If placed in the work queue and the maximum number of connections has
     connection will be started.  Our goal is to eventually have   not yet been created, a new connection will be started.  Our goal is
     a sufficient number of connections that the work queue will  to eventually have a sufficient number of connections that the work
     typically be empty.  queue will typically be empty.  parameters are:
     parameters are:  
 =item Socket open on the lonc client.  =item Socket
 =item Request data to send to the lond.  
   open on the lonc client.
   
   =item Request
   
   data to send to the lond.
   
 =cut  =cut
   
 sub QueueTransaction {  sub QueueTransaction {
     my $requestSocket = shift;  
     my $requestData   = shift;  
   
     Debug(6,"QueueTransaction: ".$requestData);      my $requestData   = shift; # This is a LondTransaction.
       my $cmd           = $requestData->getRequest();
   
       Debug(6,"QueueTransaction: ".$cmd);
   
     my $LondSocket    = $IdleConnections->pop();      my $LondSocket    = $IdleConnections->pop();
     if(!defined $LondSocket) { # Need to queue request.      if(!defined $LondSocket) { # Need to queue request.
  Debug(8,"Must queue...");   Debug(5,"Must queue...");
  $ClientQueue->enqueue($requestSocket);  
  $WorkQueue->enqueue($requestData);   $WorkQueue->enqueue($requestData);
  if($ConnectionCount < $MaxConnectionCount) {   Debug(5, "Queue Transaction startnew $ConnectionCount $LondConnecting");
     Debug(4,"Starting additional lond connection");   if(($ConnectionCount < $MaxConnectionCount)   && (! $LondConnecting)) {
     MakeLondConnection();  
       if($ConnectionRetriesLeft > 0) {
    Debug(5,"Starting additional lond connection");
    if(&MakeLondConnection() == 0) {
       EmptyQueue(); # Fail transactions, can't make connection.
       CloseAllLondConnections; # Should all be closed but...
    }
       } else {
    ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
    $LondConnecting = 0;
    EmptyQueue(); # It's worse than that ... he's dead Jim.
    CloseAllLondConnections; # Should all be closed but..
       }
  }   }
     } else { # Can start the request:      } else { # Can start the request:
  Debug(8,"Can start...");   Debug(8,"Can start...");
  StartRequest($LondSocket, $requestSocket, $requestData);   StartRequest($LondSocket,  $requestData);
     }      }
 }  }
   
 #-------------------------- Lonc UNIX socket handling ---------------------  #-------------------------- Lonc UNIX socket handling ---------------------
   
 =pod  =pod
   
 =head2 ClientRequest  =head2 ClientRequest
    Callback that is called when data can be read from the   Callback that is called when data can be read from the UNIX domain
    UNIX domain socket connecting us with an apache server process.  socket connecting us with an apache server process.
   
 =cut  =cut
   
Line 669  sub ClientRequest { Line 1376  sub ClientRequest {
     my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);      my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
     Debug(8, "rcv:  data length = ".length($thisread)      Debug(8, "rcv:  data length = ".length($thisread)
   ." read =".$thisread);    ." read =".$thisread);
     unless (defined $rv && length($thisread)) {      unless (defined $rv  && length($thisread)) {
  # Likely eof on socket.   # Likely eof on socket.
  Debug(5,"Client Socket closed on lonc for ".$RemoteHost);   Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
  close($socket);   close($socket);
  $watcher->cancel();   $watcher->cancel();
  delete($ActiveClients{$socket});   delete($ActiveClients{$socket});
    return;
     }      }
     Debug(8,"Data: ".$data." this read: ".$thisread);      Debug(8,"Data: ".$data." this read: ".$thisread);
     $data = $data.$thisread; # Append new data.      $data = $data.$thisread; # Append new data.
     $watcher->data($data);      $watcher->data($data);
     if($data =~ /(.*\n)/) { # Request entirely read.      if($data =~ /\n$/) { # Request entirely read.
    if($data eq "close_connection_exit\n") {
       Log("CRITICAL",
    "Request Close Connection ... exiting");
       CloseAllLondConnections();
       exit;
    }
  Debug(8, "Complete transaction received: ".$data);   Debug(8, "Complete transaction received: ".$data);
  QueueTransaction($socket, $data);   if($LogTransactions) {
       Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
    }
    my $Transaction = LondTransaction->new($data);
    $Transaction->SetClient($socket);
    QueueTransaction($Transaction);
  $watcher->cancel(); # Done looking for input data.   $watcher->cancel(); # Done looking for input data.
     }      }
   
 }  }
   
   #
   #     Accept a connection request for a client (lonc child) and
   #    start up an event watcher to keep an eye on input from that 
   #    Event.  This can be called both from NewClient and from
   #    ChildProcess if we are started in DieWhenIdle mode.
   # Parameters:
   #    $socket       - The listener socket.
   # Returns:
   #   NONE
   # Side Effects:
   #    An event is made to watch the accepted connection.
   #    Active clients hash is updated to reflect the new connection.
   #    The client connection count is incremented.
   #
   sub accept_client {
       my ($socket) = @_;
   
 =pod      Debug(8, "Entering accept for lonc UNIX socket\n");
 =head2  NewClient  
     Callback that is called when a connection is received on the  
     unix socket for a new client of lonc.  The callback is parameterized  
     by the event.. which is a-priori assumed to be an  io event, and therefore  
     has an fd member that is the Listener socket.   We Accept the connection  
     and register a new event on the readability of that socket:  
 =cut  
 sub NewClient {  
     Debug(6, "NewClient");  
     my $event      = shift; # Get the event parameters.  
     my $watcher    = $event->w;   
     my $socket     = $watcher->fd; # Get the event' socket.  
     my $connection = $socket->accept(); # Accept the client connection.      my $connection = $socket->accept(); # Accept the client connection.
     Debug(8,"Connection request accepted from "      Debug(8,"Connection request accepted from "
   .GetPeername($connection, AF_UNIX));    .GetPeername($connection, AF_UNIX));
Line 717  sub NewClient { Line 1440  sub NewClient {
     $ActiveClients{$connection} = $ClientConnection;      $ActiveClients{$connection} = $ClientConnection;
     $ClientConnection++;      $ClientConnection++;
 }  }
 =pod GetLoncSocketPath  
     Returns the name of the UNIX socket on which to listen for client  =pod
     connections.  
   =head2  NewClient
   
   Callback that is called when a connection is received on the unix
   socket for a new client of lonc.  The callback is parameterized by the
   event.. which is a-priori assumed to be an io event, and therefore has
   an fd member that is the Listener socket.  We Accept the connection
   and register a new event on the readability of that socket:
   
   =cut
   
   sub NewClient {
       Debug(6, "NewClient");
       my $event      = shift; # Get the event parameters.
       my $watcher    = $event->w; 
       my $socket     = $watcher->fd; # Get the event' socket.
   
       &accept_client($socket);
   }
   
   =pod
   
   =head2 GetLoncSocketPath
   
   Returns the name of the UNIX socket on which to listen for client
   connections.
   
   =head2 Parameters:
   
       host (optional)  - Name of the host socket to return.. defaults to
                          the return from GetServerHost().
   
 =cut  =cut
   
 sub GetLoncSocketPath {  sub GetLoncSocketPath {
     return $UnixSocketDir."/".GetServerHost();  
       my $host = GetServerHost(); # Default host.
       if (@_) {
    ($host)  = @_; # Override if supplied.
       }
       return $UnixSocketDir."/".$host;
 }  }
   
 =pod GetServerHost   =pod
    Returns the host whose lond we talk with.  
   =head2 GetServerHost
   
   Returns the host whose lond we talk with.
   
 =cut  =cut
 sub GetServerHost { # Stub - get this from config.  
   sub GetServerHost {
     return $RemoteHost; # Setup by the fork.      return $RemoteHost; # Setup by the fork.
 }  }
 =pod GetServerPort  
    Returns the lond port number.  =pod
   
   =head2 GetServerPort
   
   Returns the lond port number.
   
 =cut  =cut
 sub GetServerPort { # Stub - get this from config.  
   sub GetServerPort {
     return $perlvar{londPort};      return $perlvar{londPort};
 }  }
 =pod SetupLoncListener  
    Setup a lonc listener event.  The event is called when  =pod
    the socket becomes readable.. that corresponds to the   
    receipt of a new connection.  The event handler established  =head2 SetupLoncListener
    will accept the connection (creating a communcations channel), that  
    int turn will establish another event handler to subess requests.  Setup a lonc listener event.  The event is called when the socket
   becomes readable.. that corresponds to the receipt of a new
   connection.  The event handler established will accept the connection
   (creating a communcations channel), that int turn will establish
   another event handler to subess requests.
   
   =head2  Parameters:
   
      host (optional)   Name of the host to set up a unix socket to.
   
 =cut  =cut
   
 sub SetupLoncListener {  sub SetupLoncListener {
   
       my $host       = GetServerHost(); # Default host.
       if (@_) {
    ($host)    = @_ # Override host with parameter.
       }
   
     my $socket;      my $socket;
     my $SocketName = GetLoncSocketPath();      my $SocketName = GetLoncSocketPath($host);
     unlink($SocketName);      unlink($SocketName);
     unless ($socket = IO::Socket::UNIX->new(Local  => $SocketName,      unless ($socket =IO::Socket::UNIX->new(Local  => $SocketName,
     Listen => 10,       Listen => 250, 
     Type   => SOCK_STREAM)) {      Type   => SOCK_STREAM)) {
  die "Failed to create a lonc listner socket";   if($I_am_child) {
       &child_exit(-1, "Failed to create a lonc listener socket");
    } else {
       die "Failed to create a lonc listner socket";
    }
       }
       return $socket;
   }
   
   #
   #   Toggle transaction logging.
   #  Implicit inputs:  
   #     LogTransactions
   #  Implicit Outputs:
   #     LogTransactions
   sub ToggleTransactionLogging {
       print STDERR "Toggle transaction logging...\n";
       if(!$LogTransactions) {
    $LogTransactions = 1;
       } else {
    $LogTransactions = 0;
       }
   
   
       Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
   }
   
   =pod 
   
   =head2 ChildStatus
    
   Child USR1 signal handler to report the most recent status
   into the status file.
   
   We also use this to reset the retries count in order to allow the
   client to retry connections with a previously dead server.
   
   =cut
   
   sub ChildStatus {
       my $event = shift;
       my $watcher = $event->w;
   
       Debug(2, "Reporting child status because : ".$watcher->data);
       my $docdir = $perlvar{'lonDocRoot'};
       
       open(LOG,">>$docdir/lon-status/loncstatus.txt");
       flock(LOG,LOCK_EX);
       print LOG $$."\t".$RemoteHost."\t".$Status."\t".
    $RecentLogEntry."\n";
       #
       #  Write out information about each of the connections:
       #
       if ($DebugLevel > 2) {
    print LOG "Active connection statuses: \n";
    my $i = 1;
    print STDERR  "================================= Socket Status Dump:\n";
    foreach my $item (keys %ActiveConnections) {
       my $Socket = $ActiveConnections{$item}->data;
       my $state  = $Socket->GetState();
       print LOG "Connection $i State: $state\n";
       print STDERR "---------------------- Connection $i \n";
       $Socket->Dump(-1); # Ensure it gets dumped..
       $i++;
    }
     }      }
     Event->io(cb     => \&NewClient,      flock(LOG,LOCK_UN);
       poll   => 'r',      close(LOG);
       desc   => 'Lonc listener Unix Socket',      $ConnectionRetriesLeft = $ConnectionRetries;
       fd     => $socket);      UpdateStatus();
 }  }
   
 =pod  =pod
   
   =head2 SignalledToDeath
   
   Called in response to a signal that causes a chid process to die.
   
   =cut
   
   
   sub SignalledToDeath {
       my $event  = shift;
       my $watcher= $event->w;
   
       Debug(2,"Signalled to death! via ".$watcher->data);
       my ($signal) = $watcher->data;
       chomp($signal);
       Log("CRITICAL", "Abnormal exit.  Child $$ for $RemoteHost "
    ."died through "."\"$signal\"");
       #LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
   #    ."\"$signal\"");
       exit 0;
   
   }
   
   =pod
   
   =head2 ToggleDebug
   
   This sub toggles trace debugging on and off.
   
   =cut
   
   sub ToggleDebug {
       my $Current    = $DebugLevel;
          $DebugLevel = $NextDebugLevel;
          $NextDebugLevel = $Current;
   
       Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
   
   }
   
   =pod
   
 =head2 ChildProcess  =head2 ChildProcess
   
 This sub implements a child process for a single lonc daemon.  This sub implements a child process for a single lonc daemon.
   Optional parameter:
      $socket  - if provided, this is a socket already open for listen
                 on the client socket. Otherwise, a new listen is set up.
   
 =cut  =cut
   
 sub ChildProcess {  sub ChildProcess {
       #  If we are in DieWhenIdle mode, we've inherited all the
       #  events of our parent and those have to be cancelled or else
       #  all holy bloody chaos will result.. trust me, I already made
       #  >that< mistake.
   
       my $host = GetServerHost();
       foreach my $listener (keys %parent_dispatchers) {
    my $watcher = $parent_dispatchers{$listener};
    my $s       = $watcher->fd;
    if ($listener ne $host) { # Close everyone but me.
       Debug(5, "Closing listen socket for $listener");
       $s->close();
    }
    Debug(5, "Killing watcher for $listener");
   
    $watcher->cancel();
    delete($parent_dispatchers{$listener});
   
     print "Loncnew\n";      }
   
     # For now turn off signals.      #  kill off the parent's signal handlers too!  
           #
     $SIG{QUIT}  = IGNORE;  
     $SIG{HUP}   = IGNORE;  
     $SIG{USR1}  = IGNORE;  
     $SIG{INT}   = IGNORE;  
     $SIG{CHLD}  = IGNORE;  
     $SIG{__DIE__}  = IGNORE;  
   
     SetupTimer();      for my $handler (keys %parent_handlers) {
        my $watcher = $parent_handlers{$handler};
     SetupLoncListener();   $watcher->cancel();
    delete($parent_handlers{$handler});
       }
   
       $I_am_child    = 1; # Seems like in spite of it all I may still getting
                                   # parent event dispatches.. flag I'm a child.
   
   
       #
       #  Signals must be handled by the Event framework...
       #
   
       Event->signal(signal   => "QUIT",
     cb       => \&SignalledToDeath,
     data     => "QUIT");
       Event->signal(signal   => "HUP",
     cb       => \&ChildStatus,
     data     => "HUP");
       Event->signal(signal   => "USR1",
     cb       => \&ChildStatus,
     data     => "USR1");
       Event->signal(signal   => "USR2",
     cb       => \&ToggleTransactionLogging);
       Event->signal(signal   => "INT",
     cb       => \&ToggleDebug,
     data     => "INT");
   
       #  Figure out if we got passed a socket or need to open one to listen for
       #  client requests.
   
       my ($socket) = @_;
       if (!$socket) {
   
    $socket =  SetupLoncListener();
       }
       #  Establish an event to listen for client connection requests.
   
   
       Event->io(cb   => \&NewClient,
         poll => 'r',
         desc => 'Lonc Listener Unix Socket',
         fd   => $socket);
           
     $Event::Debuglevel = $DebugLevel;      $Event::DebugLevel = $DebugLevel;
           
     Debug(9, "Making initial lond connection for ".$RemoteHost);      Debug(9, "Making initial lond connection for ".$RemoteHost);
   
 # Setup the initial server connection:  # Setup the initial server connection:
           
     &MakeLondConnection();       # &MakeLondConnection(); // let first work request do it.
       
       #  If We are in diwhenidle, need to accept the connection since the
       #  event may  not fire.
   
       if ($DieWhenIdle) {
    &accept_client($socket);
       }
   
     Debug(9,"Entering event loop");      Debug(9,"Entering event loop");
     my $ret = Event::loop(); #  Start the main event loop.      my $ret = Event::loop(); #  Start the main event loop.
           
           
     die "Main event loop exited!!!";      &child_exit (-1,"Main event loop exited!!!");
 }  }
   
 #  Create a new child for host passed in:  #  Create a new child for host passed in:
   
 sub CreateChild {  sub CreateChild {
     my $host = shift;      my ($host, $socket) = @_;
   
       my $sigset = POSIX::SigSet->new(SIGINT);
       sigprocmask(SIG_BLOCK, $sigset);
     $RemoteHost = $host;      $RemoteHost = $host;
     Debug(3, "Forking off child for ".$RemoteHost);      Log("CRITICAL", "Forking server for ".$host);
     sleep(5);      my $pid          = fork;
     $pid          = fork;  
     if($pid) { # Parent      if($pid) { # Parent
  $ChildHash{$pid} = $RemoteHost;   $RemoteHost = "Parent";
    $ChildHash{$pid} = $host;
    $HostToPid{$host}= $pid;
    sigprocmask(SIG_UNBLOCK, $sigset);
   
     } else { # child.      } else { # child.
  ChildProcess;   ShowStatus("Connected to ".$RemoteHost);
    $SIG{INT} = 'DEFAULT';
    sigprocmask(SIG_UNBLOCK, $sigset);
    if(defined $socket) {
       &ChildProcess($socket);
    } else {
       ChildProcess; # Does not return.
    }
       }
   }
   
   # parent_client_connection:
   #    Event handler that processes client connections for the parent process.
   #    This sub is called when the parent is listening on a socket and
   #    a connection request arrives.  We must:
   #     Start a child process to accept the connection request.
   #     Kill our listen on the socket.
   # Parameter:
   #    event       - The event object that was created to monitor this socket.
   #                  event->w->fd is the socket.
   # Returns:
   #    NONE
   #
   sub parent_client_connection {
       if ($I_am_child) {
    #  Should not get here, but seem to anyway:
    &Debug(5," Child caught parent client connection event!!");
    my ($event) = @_;
    my $watcher = $event->w;
    $watcher->cancel(); # Try to kill it off again!!
       } else {
    &Debug(9, "parent_client_connection");
    my ($event)   = @_;
    my $watcher   = $event->w;
    my $socket    = $watcher->fd;
   
    # Lookup the host associated with this socket:
   
    my $host = $listening_to{$socket};
   
    # Start the child:
   
   
   
    &Debug(9,"Creating child for $host (parent_client_connection)");
    &CreateChild($host, $socket);
   
    # Clean up the listen since now the child takes over until it exits.
   
    $watcher->cancel(); # Nolonger listening to this event
    delete($listening_to{$socket});
    delete($parent_dispatchers{$host});
    $socket->close();
       }
   }
   
   # parent_listen:
   #    Opens a socket and starts a listen for the parent process on a client UNIX
   #    domain socket.
   #
   #    This involves:
   #       Creating a socket for listen.
   #       Removing any socket lock file
   #       Adding an event handler for this socket becoming readable
   #         To the parent's event dispatcher.
   # Parameters:
   #    loncapa_host    - LonCAPA cluster name of the host represented by the client
   #                      socket.
   # Returns:
   #    NONE
   #
   sub parent_listen {
       my ($loncapa_host) = @_;
       Debug(5, "parent_listen: $loncapa_host");
   
       my $socket    = &SetupLoncListener($loncapa_host);
       $listening_to{$socket} = $loncapa_host;
       if (!$socket) {
    die "Unable to create a listen socket for $loncapa_host";
       }
       
       my $lock_file = &GetLoncSocketPath($loncapa_host).".lock";
       unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
   
       my $watcher = Event->io(cb    => \&parent_client_connection,
         poll  => 'r',
         desc  => "Parent listener unix socket ($loncapa_host)",
         fd    => $socket);
       $parent_dispatchers{$loncapa_host} = $watcher;
   
   }
   
   
   # listen_on_all_unix_sockets:
   #    This sub initiates a listen on all unix domain lonc client sockets.
   #    This will be called in the case where we are trimming idle processes.
   #    When idle processes are trimmed, loncnew starts up with no children,
   #    and only spawns off children when a connection request occurs on the
   #    client unix socket.  The spawned child continues to run until it has
   #    been idle a while at which point it eventually exits and once more
   #    the parent picks up the listen.
   #
   #  Parameters:
   #      NONE
   #  Implicit Inputs:
   #    The configuration file that has been read in by LondConnection.
   #  Returns:
   #     NONE
   #
   sub listen_on_all_unix_sockets {
       Debug(5, "listen_on_all_unix_sockets");
       my $host_iterator      =   &LondConnection::GetHostIterator();
       while (!$host_iterator->end()) {
    my $host_entry_ref =   $host_iterator->get();
    my $host_name      = $host_entry_ref->[3];
    Debug(9, "Listen for $host_name");
    &parent_listen($host_name);
    $host_iterator->next();
       }
   }
   
   #   server_died is called whenever a child process exits.
   #   Since this is dispatched via a signal, we must process all
   #   dead children until there are no more left.  The action
   #   is to:
   #      - Remove the child from the bookeeping hashes
   #      - Re-establish a listen on the unix domain socket associated
   #        with that host.
   # Parameters:
   #    The event, but we don't actually care about it.
   sub server_died {
       &Debug(9, "server_died called...");
       
       while(1) { # Loop until waitpid nowait fails.
    my $pid = waitpid(-1, WNOHANG);
    if($pid <= 0) {
       return; # Nothing left to wait for.
    }
    # need the host to restart:
   
    my $host = $ChildHash{$pid};
    if($host) { # It's for real...
       &Debug(9, "Caught sigchild for $host");
       delete($ChildHash{$pid});
       delete($HostToPid{$host});
       &parent_listen($host);
   
    } else {
       &Debug(5, "Caught sigchild for pid not in hosts hash: $pid");
    }
     }      }
   
 }  }
   
 #  #
 #  Parent process logic pass 1:  #  Parent process logic pass 1:
 #   For each entry in the hosts table, we will  #   For each entry in the hosts table, we will
Line 826  sub CreateChild { Line 1934  sub CreateChild {
 #  Each exit gets logged and the child gets restarted.  #  Each exit gets logged and the child gets restarted.
 #  #
   
   #
   #   Fork and start in new session so hang-up isn't going to 
   #   happen without intent.
   #
   
   
   
   
   
   
   ShowStatus("Forming new session");
   my $childpid = fork;
   if ($childpid != 0) {
       sleep 4; # Give child a chacne to break to
       exit 0; # a new sesion.
   }
   #
   #   Write my pid into the pid file so I can be located
   #
   
   ShowStatus("Parent writing pid file:");
   my $execdir = $perlvar{'lonDaemons'};
   open (PIDSAVE, ">$execdir/logs/lonc.pid");
   print PIDSAVE "$$\n";
   close(PIDSAVE);
   
   
   
   if (POSIX::setsid() < 0) {
       print "Could not create new session\n";
       exit -1;
   }
   
   ShowStatus("Forking node servers");
   
   Log("CRITICAL", "--------------- Starting children ---------------");
   
   LondConnection::ReadConfig;               # Read standard config files.
 my $HostIterator = LondConnection::GetHostIterator;  my $HostIterator = LondConnection::GetHostIterator;
 while (! $HostIterator->end()) {  
   
     $hostentryref = $HostIterator->get();  if ($DieWhenIdle) {
     CreateChild($hostentryref->[0]);      $RemoteHost = "[parent]";
     $HostIterator->next();      &listen_on_all_unix_sockets();
   } else {
       
       while (! $HostIterator->end()) {
   
    my $hostentryref = $HostIterator->get();
    CreateChild($hostentryref->[0]);
    $HostHash{$hostentryref->[0]} = $hostentryref->[4];
    $HostIterator->next();
       }
 }  }
   
   $RemoteHost = "Parent Server";
   
 # Maintain the population:  # Maintain the population:
   
 while(1) {  ShowStatus("Parent keeping the flock");
     $deadchild = wait();  
     if(exists $ChildHash{$deadchild}) { # need to restart.  
  $deadhost = $ChildHash{$deadchild};  if ($DieWhenIdle) {
  delete($ChildHash{$deadchild});      # We need to setup a SIGChild event to handle the exit (natural or otherwise)
  Debug(4,"Lost child pid= ".$deadchild.      # of the children.
       "Connected to host ".$deadhost);  
  CreateChild($deadhost);      Event->signal(cb       => \&server_died,
      desc     => "Child exit handler",
      signal   => "CHLD");
   
   
       # Set up all the other signals we set up.  We'll vector them off to the
       # same subs as we would for DieWhenIdle false and, if necessary, conditionalize
       # the code there.
   
       $parent_handlers{INT} = Event->signal(cb       => \&Terminate,
     desc     => "Parent INT handler",
     signal   => "INT");
       $parent_handlers{TERM} = Event->signal(cb       => \&Terminate,
      desc     => "Parent TERM handler",
      signal   => "TERM");
       $parent_handlers{HUP}  = Event->signal(cb       => \&Restart,
      desc     => "Parent HUP handler.",
      signal   => "HUP");
       $parent_handlers{USR1} = Event->signal(cb       => \&CheckKids,
      desc     => "Parent USR1 handler",
      signal   => "USR1");
       $parent_handlers{USR2} = Event->signal(cb       => \&UpdateKids,
      desc     => "Parent USR2 handler.",
      signal   => "USR2");
       
       #  Start procdesing events.
   
       $Event::DebugLevel = $DebugLevel;
       Debug(9, "Parent entering event loop");
       my $ret = Event::loop();
       die "Main Event loop exited: $ret";
   
   
   } else {
       #
       #   Set up parent signals:
       #
       
       $SIG{INT}  = \&Terminate;
       $SIG{TERM} = \&Terminate; 
       $SIG{HUP}  = \&Restart;
       $SIG{USR1} = \&CheckKids; 
       $SIG{USR2} = \&UpdateKids; # LonManage update request.
       
       while(1) {
    my $deadchild = wait();
    if(exists $ChildHash{$deadchild}) { # need to restart.
       my $deadhost = $ChildHash{$deadchild};
       delete($HostToPid{$deadhost});
       delete($ChildHash{$deadchild});
       Log("WARNING","Lost child pid= ".$deadchild.
    "Connected to host ".$deadhost);
       Log("INFO", "Restarting child procesing ".$deadhost);
       CreateChild($deadhost);
    }
     }      }
 }  }
   
   
   =pod
   
   =head1 CheckKids
   
     Since kids do not die as easily in this implementation
   as the previous one, there  is no need to restart the
   dead ones (all dead kids get restarted when they die!!)
   The only thing this function does is to pass USR1 to the
   kids so that they report their status.
   
   =cut
   
   sub CheckKids {
       Debug(2, "Checking status of children");
       my $docdir = $perlvar{'lonDocRoot'};
       my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
       my $now=time;
       my $local=localtime($now);
       print $fh "LONC status $local - parent $$ \n\n";
       foreach my $host (keys %parent_dispatchers) {
    print $fh "LONC Parent process listening for $host\n";
       }
       foreach my $pid (keys %ChildHash) {
    Debug(2, "Sending USR1 -> $pid");
    kill 'USR1' => $pid; # Tell Child to report status.
       }
   
   }
   
   =pod
   
   =head1  UpdateKids
   
   parent's SIGUSR2 handler.  This handler:
   
   =item
   
   Rereads the hosts file.
   
   =item
    
   Kills off (via sigint) children for hosts that have disappeared.
   
   =item
   
   QUITs  children for hosts that already exist (this just forces a status display
   and resets the connection retry count for that host.
   
   =item
   
   Starts new children for hosts that have been added to the hosts.tab file since
   the start of the master program and maintains them.
   
   =cut
   
   sub UpdateKids {
   
       Log("INFO", "Updating connections via SIGUSR2");
   
       #  I'm not sure what I was thinking in the first implementation.
       # someone will have to work hard to convince me the effect is any
       # different than Restart, especially now that we don't start up 
       # per host servers automatically, may as well just restart.
       # The down side is transactions that are in flight will get timed out
       # (lost unless they are critical).
   
       &Restart();
   
   }
   
   
   =pod
   
   =head1 Restart
   
   Signal handler for HUP... all children are killed and
   we self restart.  This is an el-cheapo way to re read
   the config file.
   
   =cut
   
   sub Restart {
       &KillThemAll; # First kill all the children.
       Log("CRITICAL", "Restarting");
       my $execdir = $perlvar{'lonDaemons'};
       unlink("$execdir/logs/lonc.pid");
       exec("$executable");
   }
   
   =pod
   
   =head1 KillThemAll
   
   Signal handler that kills all children by sending them a 
   SIGHUP.  Responds to sigint and sigterm.
   
   =cut
   
   sub KillThemAll {
       Debug(2, "Kill them all!!");
       local($SIG{CHLD}) = 'IGNORE';      # Our children >will< die.
       foreach my $pid (keys %ChildHash) {
    my $serving = $ChildHash{$pid};
    ShowStatus("Nicely Killing lonc for $serving pid = $pid");
    Log("CRITICAL", "Nicely Killing lonc for $serving pid = $pid");
    kill 'QUIT' => $pid;
       }
   
   
   }
   
   
   #
   #  Kill all children via KILL.  Just in case the
   #  first shot didn't get them.
   
   sub really_kill_them_all_dammit
   {
       Debug(2, "Kill them all Dammit");
       local($SIG{CHLD} = 'IGNORE'); # In case some purist reenabled them.
       foreach my $pid (keys %ChildHash) {
    my $serving = $ChildHash{$pid};
    &ShowStatus("Nastily killing lonc for $serving pid = $pid");
    Log("CRITICAL", "Nastily killing lonc for $serving pid = $pid");
    kill 'KILL' => $pid;
    delete($ChildHash{$pid});
    my $execdir = $perlvar{'lonDaemons'};
    unlink("$execdir/logs/lonc.pid");
       }
   }
   
   =pod
   
   =head1 Terminate
    
   Terminate the system.
   
   =cut
   
   sub Terminate {
       &Log("CRITICAL", "Asked to kill children.. first be nice...");
       &KillThemAll;
       #
       #  By now they really should all be dead.. but just in case 
       #  send them all SIGKILL's after a bit of waiting:
   
       sleep(4);
       &Log("CRITICAL", "Now kill children nasty");
       &really_kill_them_all_dammit;
       Log("CRITICAL","Master process exiting");
       exit 0;
   
   }
   =pod
   
 =head1 Theory  =head1 Theory
    The event class is used to build this as a single process with  
    an event driven model.  The following events are handled:  The event class is used to build this as a single process with an
   event driven model.  The following events are handled:
   
 =item UNIX Socket connection Received  =item UNIX Socket connection Received
   
Line 863  All sockets are run in non-blocking mode Line 2230  All sockets are run in non-blocking mode
 handler prevents hung connections.  handler prevents hung connections.
   
 Key data structures:  Key data structures:
 =item RequestQueue - A queue of requests received from UNIX sockets that are  
     waiting for a chance to be forwarded on a lond connection socket.  
   
 =item ActiveConnections - A hash of lond connections that have transactions  =item RequestQueue
     in process that are available to be timed out.  
   A queue of requests received from UNIX sockets that are
   waiting for a chance to be forwarded on a lond connection socket.
   
   =item ActiveConnections
   
   A hash of lond connections that have transactions in process that are
   available to be timed out.
   
   =item ActiveTransactions
   
   A hash indexed by lond connections that contain the client reply
   socket for each connection that has an active transaction on it.
   
   =item IdleConnections
   
   A hash of lond connections that have no work to do.  These connections
   can be closed if they are idle for a long enough time.
   
 =item ActiveTransactions - A hash indexed by lond connections that  
     contain the client reply socket for each connection that has an active  
     transaction on it.  
   
 =item IdleConnections - A hash of lond connections that have no work  
     to do.  These connections can be closed if they are idle for a long  
     enough time.  
 =cut  =cut
Removed from v.1.1  
changed lines
  Added in v.1.76

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