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Diff for /loncom/loncnew between versions 1.4 and 1.101

version 1.4, 2003/04/24 10:56:55 version 1.101, 2017/02/28 05:42:06
Line 7 Line 7
 # Copyright Michigan State University Board of Trustees  # Copyright Michigan State University Board of Trustees
 #  #
 # This file is part of the LearningOnline Network with CAPA (LON-CAPA).  # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
 #  ## LON-CAPA is free software; you can redistribute it and/or modify
 # 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  # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2 of the License, or  # the Free Software Foundation; either version 2 of the License, or
 # (at your option) any later version.  # (at your option) any later version.
Line 27 Line 26
 # http://www.lon-capa.org/  # http://www.lon-capa.org/
 #  #
 #  #
 # new lonc handles n requestors spread out bver m connections to londs.  # new lonc handles n request out over 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 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 79  my %perlvar    = %{$perlvarref}; Line 72  my %perlvar    = %{$perlvarref};
 #  #
 #  parent and shared variables.  #  parent and shared variables.
   
 my %ChildHash; # by pid -> host.  my %ChildPid; # by pid -> host.
   my %ChildHost; # by host.
   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= 5*60; # Seconds to wait prior to 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 $RemoteHostId; # default lonid of host child is talking to.
   my @all_host_ids;
   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 $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 $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");
       chomp($message);
       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
   
Line 113  Returns the name of the host that a sock Line 221  Returns the name of the host that a sock
 =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 128  sub GetPeername { Line 238  sub GetPeername {
  return $peerfile;   return $peerfile;
     }      }
 }  }
 #----------------------------- Timer management ------------------------  
 =pod  =pod
   
 =head2 Debug  =head2 Debug
Line 138  Invoked to issue a debug message. Line 247  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  =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.  The child process 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:
   
       #
       #  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);
       unlink(&GetLoncSocketPath());
   
       if ($message) {
    die($message);
       } else {
    exit($exit_code);
       }
   }
   #----------------------------- Timer management ------------------------
   
   =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;
     $0 = 'lonc: '.GetServerHost()." Connection count: ".$ConnectionCount;      UpdateStatus();
     Debug(6, "Tick");  
     Debug(6, "    Current connection count: ".$ConnectionCount);  
     foreach $client (keys %ActiveClients) {  
  Debug(7, "    Have client:  with id: ".$ActiveClients{$client});  
     }  
     # Is it time to prune connection count:      # Is it time to prune connection count:
   
   
Line 176  sub Tick { Line 368  sub Tick {
        ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?         ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
  $IdleSeconds++;   $IdleSeconds++;
  if($IdleSeconds > $IdleTimeout) { # Prune a connection...   if($IdleSeconds > $IdleTimeout) { # Prune a connection...
     $Socket = $IdleConnections->pop();      my $Socket = $IdleConnections->pop();
     KillSocket($Socket, 0);      KillSocket($Socket);
       $IdleSeconds = 0; # Otherwise all connections get trimmed to fast.
       UpdateStatus();
       if(($ConnectionCount == 0)) {
    &child_exit(0);
   
       }
  }   }
     } else {      } else {
  $IdleSeconds = 0; # Reset idle count if not idle.   $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
Line 202  Trigger disconnections of idle sockets. Line 441  Trigger disconnections of idle sockets.
   
 sub SetupTimer {  sub SetupTimer {
     Debug(6, "SetupTimer");      Debug(6, "SetupTimer");
     Event->timer(interval => 1, debug => 1, cb => \&Tick );      Event->timer(interval => 1, cb => \&Tick,
    hard => 1);
 }  }
   
 =pod  =pod
Line 222  long enough, it will be shut down and re Line 462  long enough, it will be shut down and re
   
 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);
     }      }
 }  }
Line 250  sub ServerToIdle { Line 488  sub ServerToIdle {
   
 Event callback for when a client socket is writable.  Event callback for when a client socket is writable.
   
 This callback is established when a transaction reponse is  This callback is established when a transaction response is
 avaiable from lond.  The response is forwarded to the unix socket  available from lond.  The response is forwarded to the unix socket
 as it becomes writable in this sub.  as it becomes writable in this sub.
   
 Parameters:  Parameters:
Line 266  the data and Event->w->fd is the socket Line 504  the data and Event->w->fd is the socket
 sub ClientWritable {  sub ClientWritable {
     my $Event    = shift;      my $Event    = shift;
     my $Watcher  = $Event->w;      my $Watcher  = $Event->w;
       if (!defined($Watcher)) {
    &child_exit(-1,'No watcher for event in ClientWritable');
       }
     my $Data     = $Watcher->data;      my $Data     = $Watcher->data;
     my $Socket   = $Watcher->fd;      my $Socket   = $Watcher->fd;
   
Line 274  sub ClientWritable { Line 515  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.  
     # Remove that preceding string from the data.  
     # If the resulting data is empty, destroy the watcher  
     # and set up a read event handler to accept the next  
     # request.  
   
     &Debug(9,"Send result is ".$result." Defined: ".defined($result));  
     if(defined($result)) {  
  &Debug(9, "send result was defined");  
  if($result == length($Data)) { # Entire string sent.  
     &Debug(9, "ClientWritable data all written");  
     $Watcher->cancel();  
     #  
     #  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));  
  }  
   
     } else { # Error of some sort...   # $result undefined: the write failed.
    # otherwise $result is the number of bytes written.
  # Some errnos are possible:   # Remove that preceding string from the data.
  my $errno = $!;   # If the resulting data is empty, destroy the watcher
  if($errno == POSIX::EWOULDBLOCK   ||   # and set up a read event handler to accept the next
    $errno == POSIX::EAGAIN        ||   # request.
    $errno == POSIX::EINTR) {  
     # No action taken?  
  } else { # Unanticipated errno.  
     &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);  
     $Watcher->cancel; # Stop the watcher.  
     $Socket->shutdown(2); # Kill connection  
     $Socket->close(); # Close the socket.  
  }  
   
    &Debug(9,"Send result is ".$result." Defined: ".defined($result));
    if($result ne undef) {
       &Debug(9, "send result was defined");
       if($result == length($Data)) { # Entire string sent.
    &Debug(9, "ClientWritable data all written");
    $Watcher->cancel();
    #
    #  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        ||
          $errno == POSIX::EINTR) {
    # No action taken...the socket will be writable firing the event again
    # which will result in a retry of the write.
       } else { # Unanticipated errno.
    &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
    $Watcher->cancel; # Stop the watcher.
    $Socket->shutdown(2); # Kill connection
    $Socket->close(); # Close the socket.
       }
       
    }
       } else {
    $Watcher->cancel(); # A delayed request...just cancel.
    return;
     }      }
 }  }
   
Line 336  Parameters: Line 589  Parameters:
   
 =item Socket  =item Socket
   
 Socket on which the lond transaction occured.  This is a  Socket on which the lond transaction occurred.  This is a
 LondConnection. The data received is in the TransactionReply member.  LondConnection. The data received are in the TransactionReply member.
   
 =item Client  =item Transaction
   
 Unix domain socket open on the ultimate client.  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
   
     my $data   = $Socket->GetReply(); # Data to send.     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 apache client.
   
   =cut
   
   sub StartClientReply {
   
       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 362  sub CompleteTransaction { Line 650  sub CompleteTransaction {
       cb       => \&ClientWritable,        cb       => \&ClientWritable,
       data     => $data);        data     => $data);
 }  }
   
 =pod  =pod
   
 =head2 FailTransaction  =head2 FailTransaction
   
   Finishes a transaction with failure because the associated lond socket    Finishes a transaction with failure because the associated lond socket
   disconnected.  It is up to our client to retry if desired.      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:  Parameters:
   
 =item client    =item client  
     
    The UNIX domain socket open on our client.     The LondTransaction we are failing.
    
   
 =cut  =cut
   
 sub FailTransaction {  sub FailTransaction {
     my $client = shift;      my $transaction = shift;
       
       #  If the socket is dead, that's already logged.
   
     &Debug(8, "Failing transaction due to disconnect");      if ($ConnectionRetriesLeft > 0) {
     my $Serial = $ActiveClients{$client};   Log("WARNING", "Failing transaction "
     my $desc   = sprintf("Connection to lonc client %d", $Serial);      .$transaction->getLoggableRequest());
     my $data   = "error: Connection to lond lost\n";      }
       Debug(1, "Failing transaction: ".$transaction->getLoggableRequest());
     Event->io(fd     => $client,      if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
       poll   => "w",   my $client  = $transaction->getClient();
       desc   => $desc,   Debug(1," Replying con_lost to ".$transaction->getRequest());
       cb     => \&ClientWritable,   StartClientReply($transaction, "con_lost\n");
       data   => $data);      }
   
 }  }
   
 =pod  =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  =head2 KillSocket
     
 Destroys a socket.  This function can be called either when a socket  Destroys a socket.  This function can be called either when a socket
Line 410  Parameters: Line 743  Parameters:
   
 =item Restart  =item Restart
   
 nonzero if we are allowed to create a new connection.  non-zero if we are allowed to create a new connection.
   
   
 =cut  =cut
   
 sub KillSocket {  sub KillSocket {
     my $Socket = shift;      my $Socket = shift;
     my $Restart= shift;  
   
     #  If the socket came from the active connection set, delete it.      Log("WARNING", "Shutting down a socket");
     # otherwise it came from the idle set and has already been destroyed:      $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})) {      if(exists($ActiveTransactions{$Socket})) {
  delete ($ActiveTransactions{$Socket});   delete ($ActiveTransactions{$Socket});
     }      }
     if(exists($ActiveConnections{$Socket})) {      if(exists($ActiveConnections{$Socket})) {
    $ActiveConnections{$Socket}->cancel;
  delete($ActiveConnections{$Socket});   delete($ActiveConnections{$Socket});
    $ConnectionCount--;
    if ($ConnectionCount < 0) { $ConnectionCount = 0; }
     }      }
     $ConnectionCount--;      #  If the connection count has gone to zero and there is work in the
     if( ($ConnectionCount = 0) && ($Restart)) {      #  work queue, the work all gets failed with con_lost.
  MakeLondConnection();      #
       if($ConnectionCount == 0) {
    $LondConnecting = 0; # No connections so also not connecting.
    EmptyQueue();
    CloseAllLondConnections; # Should all already be closed but...
     }      }
       UpdateStatus();
 }  }
   
 =pod  =pod
Line 443  is readable.  The action is state depend Line 788  is readable.  The action is state depend
   
 =head3 State=Initialized  =head3 State=Initialized
   
 We''re waiting for the challenge, this is a no-op until the  We are waiting for the challenge, this is a no-op until the
 state changes.  state changes.
   
 =head3 State=Challenged   =head3 State=Challenged 
Line 453  The connection must echo the challenge b Line 798  The connection must echo the challenge b
   
 =head3 State=ChallengeReplied  =head3 State=ChallengeReplied
   
 The challenge has been replied to.  The we are receiveing the   The challenge has been replied to.  Then we are receiving 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
Line 468  The the key has been requested, now we a Line 824  The the key has been requested, now we a
 =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 have
 a client as well as the socket iformation, then we are   a client as well as the socket information, then we are 
 doing a transaction and the data received is relayed to the client  doing a transaction and the data received are 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
Line 487  to readable to receive the reply. Line 843  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   contain 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. Currently this means that   # bad return from socket read. Currently this means that
  # The socket has become disconnected. We fail the transaction.   # The socket has become disconnected. We fail the transaction.
   
    Log("WARNING",
       "Lond connection lost.");
  if(exists($ActiveTransactions{$Socket})) {   if(exists($ActiveTransactions{$Socket})) {
     Debug(3,"Lond connection lost failing transaction");  
     FailTransaction($ActiveTransactions{$Socket});      FailTransaction($ActiveTransactions{$Socket});
    } else {
       #  Socket is connecting and failed... need to mark
       #  no longer connecting.
      
       $LondConnecting = 0;
  }   }
  $Watcher->cancel();   $Watcher->cancel();
  KillSocket($Socket, 1);   KillSocket($Socket);
    $ConnectionRetriesLeft--;       # Counts as connection failure
  return;   return;
     }      }
     SocketDump(6,$Socket);      SocketDump(6,$Socket);
Line 521  sub LondReadable { Line 889  sub LondReadable {
     $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 {
       my $count = $Socket->GetClientData();
       Log("SUCCESS", "Connection ".$count." 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 567  sub LondReadable { Line 970  sub LondReadable {
   
   
     } else {      } else {
  # Invalid state.   # Invalid state.
  Debug(4, "Invalid state in LondReadable");   Debug(4, "Invalid state in LondReadable");
     }      }
 }  }
Line 583  event.  The action taken is very state d Line 986  event.  The action taken is very state d
 =head3 State = Connected   =head3 State = Connected 
   
 The connection is in the process of sending the 'init' hailing to the  The connection is in the process of sending the 'init' hailing to the
 lond on the remote end.  The connection object''s Writable member is  lond on the remote end.  The Writable member of the connection object
 called.  On error, ConnectionError is called to destroy the connection  is called.  On error, call ConnectionError to destroy the connection
 and remove it from the ActiveConnections hash  and remove it from the ActiveConnections hash.
   
 =head3 Initialized  =head3 Initialized
   
Line 636  is the socket on which to return a reply Line 1039  is the socket on which to return a reply
 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")         {
   
  if ($Socket->Writable() != 0) {  
     #  The write resulted in an error.  
     # We'll treat this as if the socket got disconnected:  
     if(exists($ActiveTransactions{$Socket})) {  
  Debug(3, "Lond connection lost, failing transactions");  
  FailTransaction($ActiveTransactions{$Socket});  
     }  
     $Watcher->cancel();  
     KillSocket($Socket, 1);  
     return;  
  }  
  #  "init" is being sent...   #  "init" is being sent...
    
   
     } 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 734  sub LondWritable { Line 1162  sub LondWritable {
 }  }
   
 =pod  =pod
       
   =cut
   
   
   sub QueueDelayed {
       Debug(3,"QueueDelayed called");
   
       my $path = "$perlvar{'lonSockDir'}/delayed";
   
       Debug(4, "Delayed path: ".$path);
       opendir(DIRHANDLE, $path);
   
       my $host_id_re = '(?:'.join('|',map {quotemeta($_)} (@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
   
 =head2 MakeLondConnection  =head2 MakeLondConnection
   
 Create a new lond connection object, and start it towards its initial  Create a new lond connection object, and start it towards its initial
 idleness.  Once idle, it becomes elligible to receive transactions  idleness.  Once idle, it becomes eligible to receive transactions
 from the work queue.  If the work queue is not empty when the  from the work queue.  If the work queue is not empty when the
 connection is completed and becomes idle, it will dequeue an entry and  connection is completed and becomes idle, it will dequeue an entry and
 start off on it.  start off on it.
Line 750  sub MakeLondConnection { Line 1209  sub MakeLondConnection {
   .GetServerPort());    .GetServerPort());
   
     my $Connection = LondConnection->new(&GetServerHost(),      my $Connection = LondConnection->new(&GetServerHost(),
  &GetServerPort());   &GetServerPort(),
    &GetHostId());
   
     if($Connection == undef) { # Needs to be more robust later.      if($Connection eq undef) {
  die "Failed to make a connection!!".$!."\n";   Log("CRITICAL","Failed to make a connection with lond.");
    $ConnectionRetriesLeft--;
    return 0; # Failure.
       }  else {
   
    $LondConnecting = 1; # Connection in progress.
    # 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);  
     }  
   
        my $event = Event->io(fd       => $Socket,
     $event = Event->io(fd       => $Socket,     poll     => 'w',
        poll     => 'w',     cb       => \&LondWritable,
        cb       => \&LondWritable,     data     => $Connection,
        data     => ($Connection, undef),     desc => 'Connection to lond server');
        desc => 'Connection to lond server');   $ActiveConnections{$Connection} = $event;
     $ActiveConnections{$Connection} = $event;   if ($ConnectionCount == 0) {
       &SetupTimer; # Need to handle timeouts with connections...
     $ConnectionCount++;   }
       $ConnectionCount++;
    $Connection->SetClientData($ConnectionCount);
    Debug(4, "Connection count = ".$ConnectionCount);
    if($ConnectionCount == 1) { # First Connection:
       QueueDelayed;
    }
    Log("SUCCESS", "Created connection ".$ConnectionCount
       ." to host ".GetServerHost());
    return 1; # Return success.
       }
           
 }  }
   
Line 795  reply. Line 1269  reply.
   
 =item $Client  =item $Client
   
 Connection to the client that is making this request We got the  Connection to the client that is making this request. We got the
 request from this socket, and when the request has been relayed to  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  lond and we get a reply back from lond it will get sent to this
 socket.  socket.
Line 807  The text of the request to send. Line 1281  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 849  data to send to the lond. Line 1323  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
Line 893  sub ClientRequest { Line 1378  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;
    } elsif ($data eq "reset_retries\n") {
       Log("INFO", "Resetting Connection Retries.");
       $ConnectionRetriesLeft = $ConnectionRetries;
       &UpdateStatus();
       my $Transaction = LondTransaction->new($data);
       $Transaction->SetClient($socket);
       StartClientReply($Transaction, "ok\n");
       $watcher->cancel();
       return;
    }
  Debug(8, "Complete transaction received: ".$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.
   # 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) = @_;
   
       Debug(8, "Entering accept for lonc UNIX socket\n");
       my $connection = $socket->accept(); # Accept the client connection.
       Debug(8,"Connection request accepted from "
     .GetPeername($connection, AF_UNIX));
   
   
       my $description = sprintf("Connection to lonc client %d",
         $ClientConnection);
       Debug(9, "Creating event named: ".$description);
       Event->io(cb      => \&ClientRequest,
         poll    => 'r',
         desc    => $description,
         data    => "",
         fd      => $connection);
       $ActiveClients{$connection} = $ClientConnection;
       $ClientConnection++;
   }
   
 =pod  =pod
   
Line 919  sub ClientRequest { Line 1459  sub ClientRequest {
 Callback that is called when a connection is received on the unix  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  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  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  an fd member that is the Listener socket.  We accept the connection
 and register a new event on the readability of that socket:  and register a new event on the readability of that socket:
   
 =cut  =cut
Line 929  sub NewClient { Line 1469  sub NewClient {
     my $event      = shift; # Get the event parameters.      my $event      = shift; # Get the event parameters.
     my $watcher    = $event->w;       my $watcher    = $event->w; 
     my $socket     = $watcher->fd; # Get the event' socket.      my $socket     = $watcher->fd; # Get the event' socket.
     my $connection = $socket->accept(); # Accept the client connection.  
     Debug(8,"Connection request accepted from "  
   .GetPeername($connection, AF_UNIX));  
   
   
     my $description = sprintf("Connection to lonc client %d",      &accept_client($socket);
       $ClientConnection);  
     Debug(9, "Creating event named: ".$description);  
     Event->io(cb      => \&ClientRequest,  
       poll    => 'r',  
       desc    => $description,  
       data    => "",  
       fd      => $connection);  
     $ActiveClients{$connection} = $ClientConnection;  
     $ClientConnection++;  
 }  }
   
 =pod  =pod
Line 953  sub NewClient { Line 1480  sub NewClient {
 Returns the name of the UNIX socket on which to listen for client  Returns the name of the UNIX socket on which to listen for client
 connections.  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  =pod
Line 967  Returns the host whose lond we talk with Line 1504  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  =pod
   
   =head2 GetServerId
   
   Returns the hostid whose lond we talk with.
   
   =cut
   
   sub GetHostId {
       return $RemoteHostId; # Setup by the fork.
   }
   
   =pod
   
 =head2 GetServerPort  =head2 GetServerPort
   
 Returns the lond port number.  Returns the lond port number.
   
 =cut  =cut
   
 sub GetServerPort { # Stub - get this from config.  sub GetServerPort {
     return $perlvar{londPort};      return $perlvar{londPort};
 }  }
   
Line 990  sub GetServerPort {  # Stub - get this f Line 1539  sub GetServerPort {  # Stub - get this f
 Setup a lonc listener event.  The event is called when the socket  Setup a lonc listener event.  The event is called when the socket
 becomes readable.. that corresponds to the receipt of a new  becomes readable.. that corresponds to the receipt of a new
 connection.  The event handler established will accept the connection  connection.  The event handler established will accept the connection
 (creating a communcations channel), that int turn will establish  (creating a communications channel), that in turn will establish
 another event handler to subess requests.  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 ($host,$SocketName) = @_;
       if (!$host) { $host = &GetServerHost(); }
       if (!$SocketName) { $SocketName = &GetLoncSocketPath($host); }
   
   
     my $socket;  
     my $SocketName = GetLoncSocketPath();  
     unlink($SocketName);      unlink($SocketName);
     unless ($socket = IO::Socket::UNIX->new(Local  => $SocketName,  
     Listen => 10,       my $socket;
       unless ($socket =IO::Socket::UNIX->new(Local  => $SocketName,
       Listen => 250, 
     Type   => SOCK_STREAM)) {      Type   => SOCK_STREAM)) {
  die "Failed to create a lonc listner socket";   if($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
   
   =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  =pod
Line 1016  sub SetupLoncListener { Line 1678  sub SetupLoncListener {
 =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 listening
                 on the client socket. Otherwise, a new listener is set up.
   
 =cut  =cut
   
 sub ChildProcess {  sub ChildProcess {
       #  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");
   
     print "Loncnew\n";   $watcher->cancel();
    delete($parent_dispatchers{$listener});
   
     # For now turn off signals.      }
       
     $SIG{QUIT}  = IGNORE;  
     $SIG{HUP}   = IGNORE;  
     $SIG{USR1}  = IGNORE;  
     $SIG{INT}   = IGNORE;  
     $SIG{CHLD}  = IGNORE;  
     $SIG{__DIE__}  = IGNORE;  
   
     SetupTimer();      #  kill off the parent's signal handlers too!  
           #
     SetupLoncListener();  
       for my $handler (keys %parent_handlers) {
    my $watcher = $parent_handlers{$handler};
    $watcher->cancel();
    delete($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");
   
       # Block the pipe signal we'll get when the socket disconnects.  We detect 
       # socket disconnection via send/receive failures. On disconnect, the
       # socket becomes readable .. which will force the disconnect detection.
   
       my $set = POSIX::SigSet->new(SIGPIPE);
       sigprocmask(SIG_BLOCK, $set);
   
       #  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.
       
       #  need to accept the connection since the event may  not fire.
   
       &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, $hostid) = @_;
   
       my $sigset = POSIX::SigSet->new(SIGINT);
       sigprocmask(SIG_BLOCK, $sigset);
     $RemoteHost = $host;      $RemoteHost = $host;
     Debug(3, "Forking off child for ".$RemoteHost);      ShowStatus('Parent keeping the flock'); # Update time in status message.
     sleep(5);      Log("CRITICAL", "Forking server for ".$host);
     $pid          = fork;      my $pid          = fork;
     if($pid) { # Parent      if($pid) { # Parent
  $ChildHash{$pid} = $RemoteHost;   $RemoteHost = "Parent";
    $ChildPid{$pid} = $host;
    sigprocmask(SIG_UNBLOCK, $sigset);
    undef(@all_host_ids);
     } else { # child.      } else { # child.
  ChildProcess;   $RemoteHostId = $hostid;
    ShowStatus("Connected to ".$RemoteHost);
    $SIG{INT} = 'DEFAULT';
    sigprocmask(SIG_UNBLOCK, $sigset);
    &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;
    my $connection = $socket->accept(); # Accept the client connection.
    Event->io(cb      => \&get_remote_hostname,
     poll    => 'r',
     data    => "",
     fd      => $connection);
       }
   }
   
   sub get_remote_hostname {
       my ($event)   = @_;
       my $watcher   = $event->w;
       my $socket    = $watcher->fd;
   
       my $thisread;
       my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
       Debug(8, "rcv:  data length = ".length($thisread)." read =".$thisread);
       if (!defined($rv) || length($thisread) == 0) {
    # Likely eof on socket.
    Debug(5,"Client Socket closed on lonc for p_c_c");
    close($socket);
    $watcher->cancel();
    return;
     }      }
   
       my $data    = $watcher->data().$thisread;
       $watcher->data($data);
       if($data =~ /\n$/) { # Request entirely read.
    chomp($data);
       } else {
    return;
       }
   
       &Debug(5,"Creating child for $data (parent_client_connection)");
       (my $hostname,my $lonid,@all_host_ids) = split(':',$data);
       $ChildHost{$hostname}++;
       if ($ChildHost{$hostname} == 1) {
    &CreateChild($hostname,$lonid);
       } else {
    &Log('WARNING',"Request for a second child on $hostname");
       }
       # Clean up the listen since now the child takes over until it exits.
       $watcher->cancel(); # Nolonger listening to this event
       $socket->send("done\n");
       $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 ($socket,$file);
       if (!$loncapa_host) {
    $loncapa_host = 'common_parent';
    $file         = $perlvar{'lonSockCreate'};
       } else {
    $file         = &GetLoncSocketPath($loncapa_host);
       }
       $socket = &SetupLoncListener($loncapa_host,$file);
   
       $listening_to{$socket} = $loncapa_host;
       if (!$socket) {
    die "Unable to create a listen socket for $loncapa_host";
       }
       
       my $lock_file = $file.".lock";
       unlink($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)",
     data => "",
     fd    => $socket);
       $parent_dispatchers{$loncapa_host} = $watcher;
   
   }
   
   sub parent_clean_up {
       my ($loncapa_host) = @_;
       Debug(1, "parent_clean_up: $loncapa_host");
   
       my $socket_file = &GetLoncSocketPath($loncapa_host);
       unlink($socket_file); # No problem if it doesn't exist yet [startup e.g.]
       my $lock_file   = $socket_file.".lock";
       unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
   }
   
   
   
   #    This sub initiates a listen on the common unix domain lonc client socket.
   #    loncnew starts up with no children, and only spawns off children when a
   #    connection request occurs on the common 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_common_socket {
       Debug(5, "listen_on_common_socket");
       &parent_listen();
   }
   
   #   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 = $ChildPid{$pid};
    if($host) { # It's for real...
       &Debug(9, "Caught sigchild for $host");
       delete($ChildPid{$pid});
       delete($ChildHost{$host});
       &parent_clean_up($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 1076  sub CreateChild { Line 1993  sub CreateChild {
 #  Each exit gets logged and the child gets restarted.  #  Each exit gets logged and the child gets restarted.
 #  #
   
 my $HostIterator = LondConnection::GetHostIterator;  #
 while (! $HostIterator->end()) {  #   Fork and start in new session so hang-up isn't going to 
   #   happen without intent.
   #
   
   
   
     $hostentryref = $HostIterator->get();  
     CreateChild($hostentryref->[0]);  
     $HostIterator->next();  
   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.
   
   $RemoteHost = "[parent]";
   &listen_on_common_socket();
   
   $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};  # We need to setup a SIGChild event to handle the exit (natural or otherwise)
  delete($ChildHash{$deadchild});  # of the children.
  Debug(4,"Lost child pid= ".$deadchild.  
       "Connected to host ".$deadhost);  Event->signal(cb       => \&server_died,
  CreateChild($deadhost);        desc     => "Child exit handler",
         signal   => "CHLD");
   
   
   # Set up all the other signals we set up.
   
   $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       => \&KillThemAll,
          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";
   
   =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 %ChildPid) {
    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).
   
       &KillThemAll();
       LondConnection->ResetReadConfig();
   }
   
   
   =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.
       LondConnection->ResetReadConfig();
       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.
       # but we need to catch their death and cleanup after them in case this is 
       # a restart set of kills
       my @allpids = keys(%ChildPid);
       foreach my $pid (@allpids) {
    my $serving = $ChildPid{$pid};
    ShowStatus("Nicely Killing lonc for $serving pid = $pid");
    Log("CRITICAL", "Nicely Killing lonc for $serving pid = $pid");
    kill 'QUIT' => $pid;
       }
       ShowStatus("Finished killing child processes off.");
   }
   
   
   #
   #  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 %ChildPid) {
    my $serving = $ChildPid{$pid};
    &ShowStatus("Nastily killing lonc for $serving pid = $pid");
    Log("CRITICAL", "Nastily killing lonc for $serving pid = $pid");
    kill 'KILL' => $pid;
    delete($ChildPid{$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;
   
 }  }
   
   sub my_hostname {
       use Sys::Hostname;
       my $name = &hostname();
       &Debug(9,"Name is $name");
       return $name;
   }
   
   =pod
   
 =head1 Theory  =head1 Theory
   
 The event class is used to build this as a single process with an  The event class is used to build this as a single process with an
Line 1136  A hash of lond connections that have no Line 2282  A hash of lond connections that have no
 can be closed if they are idle for a long enough time.  can be closed if they are idle for a long enough time.
   
 =cut  =cut
   
   =pod
   
   =head1 Log messages
   
   The following is a list of log messages that can appear in the 
   lonc.log file.  Each log file has a severity and a message.
   
   =over 2
   
   =item Warning  A socket timeout was detected
   
   If there are pending transactions in the socket's queue,
   they are failed (saved if critical).  If the connection
   retry count gets exceeded by this, the
   remote host is marked as dead.
   Called when timeouts occurred during the connection and
   connection dialog with a remote host.
   
   =item Critical Host makred DEAD <hostname>   
   
   The numer of retry counts for contacting a host was
   exceeded. The host is marked dead an no 
   further attempts will be made by that child.
   
   =item Info lonc pipe client hung up on us     
   
   Write to the client pipe indicated no data transferred
   Socket to remote host is shut down.  Reply to the client 
   is discarded.  Note: This is commented out in &ClientWriteable
   
   =item Success  Reply from lond: <data>   
   
   Can be enabled for debugging by setting LogTransactions to nonzero.
   Indicates a successful transaction with lond, <data> is the data received
   from the remote lond.
   
   =item Success A delayed transaction was completed  
   
   A transaction that must be reliable was executed and completed
   as lonc restarted.  This is followed by a mesage of the form
   
     S: client-name : request
   
   =item WARNING  Failing transaction <cmd>:<subcmd>  
   
   Transaction failed on a socket, but the failure retry count for the remote
   node has not yet been exhausted (the node is not yet marked dead).
   cmd is the command, subcmd is the subcommand.  This results from a con_lost
   when communicating with lond.
   
   =item WARNING Shutting down a socket     
   
   Called when a socket is being closed to lond.  This is emitted both when 
   idle pruning is being done and when the socket has been disconnected by the remote.
   
   =item WARNING Lond connection lost.
   
   Called when a read from lond's socket failed indicating lond has closed the 
   connection or died.  This should be followed by one or more
   
    "WARNING Failing transaction..." msgs for each in-flight or queued transaction.
   
   =item INFO Connected to lond version:  <version> 
   
   When connection negotiation is complete, the lond version is requested and logged here.
   
   =item SUCCESS Connection n to host now ready for action
   
   Emitted when connection has been completed with lond. n is then number of 
   concurrent connections and host, the host to which the connection has just
   been established.
   
   =item WARNING Connection to host has been disconnected
   
   Write to a lond resulted in failure status.  Connection to lond is dropped.
   
   =item SUCCESS Created connection n to host host 
   
   Initial connection request to host..(before negotiation).
   
   =item CRITICAL Request Close Connection ... exiting
   
   Client has sent "close_connection_exit"   The loncnew server is exiting.
   
   =item INFO Resetting Connection Retries 
   
   Client has sent "reset_retries" The lond connection retries are reset to zero for the
   corresponding lond.
   
   =item SUCCESS Transaction <data>
   
   Only emitted if the global variable $LogTransactions was set to true.
   A client has requested a lond transaction <data> is the contents of the request.
   
   =item SUCCESS Toggled transaction logging <LogTransactions>
                                       
   The state of the $LogTransactions global has been toggled, and its current value
   (after being toggled) is displayed.  When non zero additional logging of transactions
   is enabled for debugging purposes.  Transaction logging is toggled on receipt of a USR2
   signal.
   
   =item CRITICAL Abnormal exit. Child <pid> for <host> died thorugh signal.
   
   QUIT signal received.  lonc child process is exiting.
   
   =item SUCCESS New debugging level for <RemoteHost> now <DebugLevel>
                                       
   Debugging toggled for the host loncnew is talking with.
   Currently debugging is a level based scheme with higher number 
   conveying more information.  The daemon starts out at
   DebugLevel 0 and can toggle back and forth between that and
   DebugLevel 2  These are controlled by
   the global variables $DebugLevel and $NextDebugLevel
   The debug level can go up to 9.
   SIGINT toggles the debug level.  The higher the debug level the 
   more debugging information is spewed.  See the Debug
   sub in loncnew.
   
   =item CRITICAL Forking server for host  
   
   A child is being created to service requests for the specified host.
   
   
   =item WARNING Request for a second child on hostname
                                       
   Somehow loncnew was asked to start a second child on a host that already had a child
   servicing it.  This request is not honored, but themessage is emitted.  This could happen
   due to a race condition.  When a client attempts to contact loncnew for a new host, a child
   is forked off to handle the requests for that server.  The parent then backs off the Unix
   domain socket leaving it for the child to service all requests.  If in the time between
   creating the child, and backing off, a new connection request comes in to the unix domain
   socket, this could trigger (unlikely but remotely possible),.
   
   =item CRITICAL ------ Starting Children ----
   
   This message should probably be changed to "Entering event loop"  as the loncnew only starts
   children as needed.  This message is emitted as new events are established and
   the event processing loop is entered.
   
   =item INFO Updating connections via SIGUSR2
                                       
   SIGUSR2 received. The original code would kill all clients, re-read the host file,
   then restart children for each host.  Now that children are started on demand, this
   just kills all child processes and lets requests start them as needed again.
   
   
   =item CRITICAL Restarting
   
   SigHUP received.  all the children are killed and the script exec's itself to start again.
   
   =item CRITICAL Nicely killing lonc for host pid = <pid>
   
   Attempting to kill the child that is serving the specified host (pid given) cleanly via
   SIGQUIT.  The child should handle that, clean up nicely and exit.
   
   =item CRITICAL Nastily killing lonc for host pid = <pid>
   
   The child specified did not die when requested via SIGQUIT.  Therefore it is killed
   via SIGKILL.
   
   =item CRITICAL Asked to kill children.. first be nice..
   
   In the parent's INT handler.  INT kills the child processes.  This inidicate loncnew
   is about to attempt to kill all known children via SIGQUIT.  This message should be followed 
   by one "Nicely killing" message for each extant child.
   
   =item CRITICAL Now kill children nasty 
   
   In the parent's INT handler. remaining children are about to be killed via
   SIGKILL. Should be followed by a Nastily killing... for each lonc child that 
   refused to die.
   
   =item CRITICAL Master process exiting
   
   In the parent's INT handler. just prior to the exit 0 call.
   
   =back
   
   =cut
Removed from v.1.4  
changed lines
  Added in v.1.101

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