Annotation of loncom/loncnew, revision 1.50

1.1       foxr        1: #!/usr/bin/perl
1.2       albertel    2: # The LearningOnline Network with CAPA
                      3: # lonc maintains the connections to remote computers
                      4: #
1.50    ! albertel    5: # $Id: loncnew,v 1.49 2004/06/17 22:37:06 foxr Exp $
1.2       albertel    6: #
                      7: # Copyright Michigan State University Board of Trustees
                      8: #
                      9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
1.17      foxr       10: ## LON-CAPA is free software; you can redistribute it and/or modify
1.2       albertel   11: # it under the terms of the GNU General Public License as published by
                     12: # the Free Software Foundation; either version 2 of the License, or
                     13: # (at your option) any later version.
                     14: #
                     15: # LON-CAPA is distributed in the hope that it will be useful,
                     16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
                     17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     18: # GNU General Public License for more details.
                     19: #
                     20: # You should have received a copy of the GNU General Public License
                     21: # along with LON-CAPA; if not, write to the Free Software
                     22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
                     23: #
                     24: # /home/httpd/html/adm/gpl.txt
                     25: #
                     26: # http://www.lon-capa.org/
                     27: #
1.1       foxr       28: #
1.15      foxr       29: # new lonc handles n request out bver m connections to londs.
1.1       foxr       30: # This module is based on the Event class.
                     31: #   Development iterations:
                     32: #    - Setup basic event loop.   (done)
                     33: #    - Add timer dispatch.       (done)
                     34: #    - Add ability to accept lonc UNIX domain sockets.  (done)
                     35: #    - Add ability to create/negotiate lond connections (done).
1.7       foxr       36: #    - Add general logic for dispatching requests and timeouts. (done).
                     37: #    - Add support for the lonc/lond requests.          (done).
1.38      foxr       38: #    - Add logging/status monitoring.                    (done)
                     39: #    - Add Signal handling - HUP restarts. USR1 status report. (done)
1.7       foxr       40: #    - Add Configuration file I/O                       (done).
1.38      foxr       41: #    - Add management/status request interface.         (done)
1.8       foxr       42: #    - Add deferred request capability.                  (done)
1.38      foxr       43: #    - Detect transmission timeouts.                     (done)
1.7       foxr       44: #
                     45: 
1.23      foxr       46: use strict;
1.1       foxr       47: use lib "/home/httpd/lib/perl/";
                     48: use Event qw(:DEFAULT );
                     49: use POSIX qw(:signal_h);
1.12      foxr       50: use POSIX;
1.1       foxr       51: use IO::Socket;
                     52: use IO::Socket::INET;
                     53: use IO::Socket::UNIX;
1.9       foxr       54: use IO::File;
1.6       foxr       55: use IO::Handle;
1.1       foxr       56: use Socket;
                     57: use Crypt::IDEA;
                     58: use LONCAPA::Queue;
                     59: use LONCAPA::Stack;
                     60: use LONCAPA::LondConnection;
1.7       foxr       61: use LONCAPA::LondTransaction;
1.1       foxr       62: use LONCAPA::Configuration;
                     63: use LONCAPA::HashIterator;
                     64: 
                     65: 
                     66: # Read the httpd configuration file to get perl variables
                     67: # normally set in apache modules:
                     68: 
                     69: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
                     70: my %perlvar    = %{$perlvarref};
                     71: 
                     72: #
                     73: #  parent and shared variables.
                     74: 
                     75: my %ChildHash;			# by pid -> host.
1.26      foxr       76: my %HostToPid;			# By host -> pid.
                     77: my %HostHash;			# by loncapaname -> IP.
1.1       foxr       78: 
                     79: 
1.9       foxr       80: my $MaxConnectionCount = 10;	# Will get from config later.
1.1       foxr       81: my $ClientConnection = 0;	# Uniquifier for client events.
                     82: 
1.9       foxr       83: my $DebugLevel = 0;
1.29      foxr       84: my $NextDebugLevel= 2;		# So Sigint can toggle this.
1.50    ! albertel   85: my $IdleTimeout= 600;		# Wait 10 minutes before pruning connections.
1.1       foxr       86: 
1.39      foxr       87: my $LogTransactions = 0;	# When True, all transactions/replies get logged.
                     88: 
1.1       foxr       89: #
                     90: #  The variables below are only used by the child processes.
                     91: #
                     92: my $RemoteHost;			# Name of host child is talking to.
1.20      albertel   93: my $UnixSocketDir= $perlvar{'lonSockDir'};
1.1       foxr       94: my $IdleConnections = Stack->new(); # Set of idle connections
                     95: my %ActiveConnections;		# Connections to the remote lond.
1.7       foxr       96: my %ActiveTransactions;		# LondTransactions in flight.
1.1       foxr       97: my %ActiveClients;		# Serial numbers of active clients by socket.
                     98: my $WorkQueue       = Queue->new(); # Queue of pending transactions.
                     99: my $ConnectionCount = 0;
1.4       foxr      100: my $IdleSeconds     = 0;	# Number of seconds idle.
1.9       foxr      101: my $Status          = "";	# Current status string.
1.14      foxr      102: my $RecentLogEntry  = "";
1.30      foxr      103: my $ConnectionRetries=2;	# Number of connection retries allowed.
                    104: my $ConnectionRetriesLeft=2;	# Number of connection retries remaining.
1.40      foxr      105: my $LondVersion     = "unknown"; # Version of lond we talk with.
1.49      foxr      106: my $KeyMode         = "";       # e.g. ssl, local, insecure from last connect.
1.1       foxr      107: 
                    108: #
1.9       foxr      109: #   The hash below gives the HTML format for log messages
                    110: #   given a severity.
                    111: #    
                    112: my %LogFormats;
                    113: 
1.45      albertel  114: $LogFormats{"CRITICAL"} = "<font color='red'>CRITICAL: %s</font>";
                    115: $LogFormats{"SUCCESS"}  = "<font color='green'>SUCCESS: %s</font>";
                    116: $LogFormats{"INFO"}     = "<font color='yellow'>INFO: %s</font>";
                    117: $LogFormats{"WARNING"}  = "<font color='blue'>WARNING: %s</font>";
1.9       foxr      118: $LogFormats{"DEFAULT"}  = " %s ";
                    119: 
1.10      foxr      120: 
                    121: 
                    122: =pod
                    123: 
                    124: =head2 LogPerm
                    125: 
                    126: Makes an entry into the permanent log file.
                    127: 
                    128: =cut
                    129: sub LogPerm {
                    130:     my $message=shift;
                    131:     my $execdir=$perlvar{'lonDaemons'};
                    132:     my $now=time;
                    133:     my $local=localtime($now);
                    134:     my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
                    135:     print $fh "$now:$message:$local\n";
                    136: }
1.9       foxr      137: 
                    138: =pod
                    139: 
                    140: =head2 Log
                    141: 
                    142: Logs a message to the log file.
                    143: Parameters:
                    144: 
                    145: =item severity
                    146: 
                    147: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
                    148: format string used to format the message.  if the severity is
                    149: not a defined severity the Default format string is used.
                    150: 
                    151: =item message
                    152: 
                    153: The base message.  In addtion to the format string, the message
                    154: will be appended to a string containing the name of our remote
                    155: host and the time will be formatted into the message.
                    156: 
                    157: =cut
                    158: 
                    159: sub Log {
1.47      foxr      160: 
                    161:     my ($severity, $message) = @_;
                    162: 
1.9       foxr      163:     if(!$LogFormats{$severity}) {
                    164: 	$severity = "DEFAULT";
                    165:     }
                    166: 
                    167:     my $format = $LogFormats{$severity};
                    168:     
                    169:     #  Put the window dressing in in front of the message format:
                    170: 
                    171:     my $now   = time;
                    172:     my $local = localtime($now);
                    173:     my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
                    174:     my $finalformat = $finalformat.$format."\n";
                    175: 
                    176:     # open the file and put the result.
                    177: 
                    178:     my $execdir = $perlvar{'lonDaemons'};
                    179:     my $fh      = IO::File->new(">>$execdir/logs/lonc.log");
                    180:     my $msg = sprintf($finalformat, $message);
1.14      foxr      181:     $RecentLogEntry = $msg;
1.9       foxr      182:     print $fh $msg;
                    183:     
1.10      foxr      184:     
1.9       foxr      185: }
1.6       foxr      186: 
1.3       albertel  187: 
1.1       foxr      188: =pod
1.3       albertel  189: 
                    190: =head2 GetPeerName
                    191: 
                    192: Returns the name of the host that a socket object is connected to.
                    193: 
1.1       foxr      194: =cut
                    195: 
                    196: sub GetPeername {
1.47      foxr      197: 
                    198: 
                    199:     my ($connection, $AdrFamily) = @_;
                    200: 
1.1       foxr      201:     my $peer       = $connection->peername();
                    202:     my $peerport;
                    203:     my $peerip;
                    204:     if($AdrFamily == AF_INET) {
                    205: 	($peerport, $peerip) = sockaddr_in($peer);
1.23      foxr      206: 	my $peername    = gethostbyaddr($peerip, $AdrFamily);
1.1       foxr      207: 	return $peername;
                    208:     } elsif ($AdrFamily == AF_UNIX) {
                    209: 	my $peerfile;
                    210: 	($peerfile) = sockaddr_un($peer);
                    211: 	return $peerfile;
                    212:     }
                    213: }
                    214: =pod
1.3       albertel  215: 
1.1       foxr      216: =head2 Debug
1.3       albertel  217: 
                    218: Invoked to issue a debug message.
                    219: 
1.1       foxr      220: =cut
1.3       albertel  221: 
1.1       foxr      222: sub Debug {
1.47      foxr      223: 
                    224:     my ($level, $message) = @_;
                    225: 
1.1       foxr      226:     if ($level <= $DebugLevel) {
1.23      foxr      227: 	Log("INFO", "-Debug- $message host = $RemoteHost");
1.1       foxr      228:     }
                    229: }
                    230: 
                    231: sub SocketDump {
1.47      foxr      232: 
                    233:     my ($level, $socket) = @_;
                    234: 
1.1       foxr      235:     if($level <= $DebugLevel) {
1.48      foxr      236: 	$socket->Dump(-1);	# Ensure it will get dumped.
1.1       foxr      237:     }
                    238: }
1.3       albertel  239: 
1.1       foxr      240: =pod
1.3       albertel  241: 
1.5       foxr      242: =head2 ShowStatus
                    243: 
                    244:  Place some text as our pid status.
1.10      foxr      245:  and as what we return in a SIGUSR1
1.5       foxr      246: 
                    247: =cut
                    248: sub ShowStatus {
1.10      foxr      249:     my $state = shift;
                    250:     my $now = time;
                    251:     my $local = localtime($now);
                    252:     $Status   = $local.": ".$state;
                    253:     $0='lonc: '.$state.' '.$local;
1.5       foxr      254: }
                    255: 
                    256: =pod
                    257: 
1.15      foxr      258: =head 2 SocketTimeout
                    259: 
                    260:     Called when an action on the socket times out.  The socket is 
                    261:    destroyed and any active transaction is failed.
                    262: 
                    263: 
                    264: =cut
                    265: sub SocketTimeout {
                    266:     my $Socket = shift;
1.38      foxr      267:     Log("WARNING", "A socket timeout was detected");
                    268:     Debug(0, " SocketTimeout called: ");
1.48      foxr      269:     $Socket->Dump(0);
1.42      foxr      270:     if(exists($ActiveTransactions{$Socket})) {
1.43      albertel  271: 	FailTransaction($ActiveTransactions{$Socket});
1.42      foxr      272:     }
1.22      foxr      273:     KillSocket($Socket);	# A transaction timeout also counts as
                    274:                                 # a connection failure:
                    275:     $ConnectionRetriesLeft--;
1.42      foxr      276:     if($ConnectionRetriesLeft <= 0) {
                    277: 	Log("CRITICAL", "Host marked dead: ".GetServerHost());
                    278:     }
                    279: 
1.15      foxr      280: }
1.35      foxr      281: #----------------------------- Timer management ------------------------
1.15      foxr      282: 
                    283: =pod
                    284: 
1.1       foxr      285: =head2 Tick
1.3       albertel  286: 
                    287: Invoked  each timer tick.
                    288: 
1.1       foxr      289: =cut
                    290: 
1.5       foxr      291: 
1.1       foxr      292: sub Tick {
                    293:     my $client;
1.22      foxr      294:     if($ConnectionRetriesLeft > 0) {
                    295: 	ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
1.49      foxr      296: 		   ." Retries remaining: ".$ConnectionRetriesLeft
                    297: 		   ." ($KeyMode)");
1.22      foxr      298:     } else {
                    299: 	ShowStatus(GetServerHost()." >> DEAD <<");
                    300:     }
1.4       foxr      301:     # Is it time to prune connection count:
                    302: 
                    303: 
                    304:     if($IdleConnections->Count()  && 
                    305:        ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
                    306: 	$IdleSeconds++;
                    307: 	if($IdleSeconds > $IdleTimeout) { # Prune a connection...
1.23      foxr      308: 	    my $Socket = $IdleConnections->pop();
1.6       foxr      309: 	    KillSocket($Socket);
1.4       foxr      310: 	}
                    311:     } else {
                    312: 	$IdleSeconds = 0;	# Reset idle count if not idle.
                    313:     }
1.15      foxr      314:     #
                    315:     #  For each inflight transaction, tick down its timeout counter.
                    316:     #
1.35      foxr      317: 
1.34      albertel  318:     foreach my $item (keys %ActiveConnections) {
                    319: 	my $State = $ActiveConnections{$item}->data->GetState();
1.35      foxr      320: 	if ($State ne 'Idle') {
1.34      albertel  321: 	    Debug(5,"Ticking Socket $State $item");
                    322: 	    $ActiveConnections{$item}->data->Tick();
                    323: 	}
1.15      foxr      324:     }
1.5       foxr      325:     # Do we have work in the queue, but no connections to service them?
                    326:     # If so, try to make some new connections to get things going again.
                    327:     #
                    328:     
                    329:     my $Requests = $WorkQueue->Count();
1.10      foxr      330:     if (($ConnectionCount == 0)  && ($Requests > 0)) { 
                    331: 	if ($ConnectionRetriesLeft > 0) {
                    332: 	    my $Connections = ($Requests <= $MaxConnectionCount) ?
                    333: 		$Requests : $MaxConnectionCount;
1.29      foxr      334: 	    Debug(5,"Work but no connections, start ".$Connections." of them");
1.22      foxr      335: 	    my $successCount = 0;
1.23      foxr      336: 	    for (my $i =0; $i < $Connections; $i++) {
1.22      foxr      337: 		$successCount += MakeLondConnection();
                    338: 	    }
                    339: 	    if($successCount == 0) { # All connections failed:
1.29      foxr      340: 		Debug(5,"Work in queue failed to make any connectiouns\n");
1.22      foxr      341: 		EmptyQueue();	# Fail pending transactions with con_lost.
1.42      foxr      342: 		CloseAllLondConnections(); # Should all be closed but....
1.10      foxr      343: 	    }
                    344: 	} else {
1.22      foxr      345: 	    ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
1.29      foxr      346: 	    Debug(5,"Work in queue, but gave up on connections..flushing\n");
1.10      foxr      347: 	    EmptyQueue();	# Connections can't be established.
1.42      foxr      348: 	    CloseAllLondConnections(); # Should all already be closed but...
1.5       foxr      349: 	}
                    350:        
                    351:     }
1.49      foxr      352:     if ($ConnectionCount == 0) {
                    353: 	$KeyMode = ""; 
                    354:     }
1.1       foxr      355: }
                    356: 
                    357: =pod
1.3       albertel  358: 
1.1       foxr      359: =head2 SetupTimer
                    360: 
1.3       albertel  361: Sets up a 1 per sec recurring timer event.  The event handler is used to:
1.1       foxr      362: 
1.3       albertel  363: =item
                    364: 
                    365: Trigger timeouts on communications along active sockets.
                    366: 
                    367: =item
                    368: 
                    369: Trigger disconnections of idle sockets.
1.1       foxr      370: 
                    371: =cut
                    372: 
                    373: sub SetupTimer {
                    374:     Debug(6, "SetupTimer");
1.33      foxr      375:     Event->timer(interval => 1, cb => \&Tick );
1.1       foxr      376: }
1.3       albertel  377: 
1.1       foxr      378: =pod
1.3       albertel  379: 
1.1       foxr      380: =head2 ServerToIdle
1.3       albertel  381: 
                    382: This function is called when a connection to the server is
                    383: ready for more work.
                    384: 
                    385: If there is work in the Work queue the top element is dequeued
1.1       foxr      386: and the connection will start to work on it.  If the work queue is
                    387: empty, the connection is pushed on the idle connection stack where
                    388: it will either get another work unit, or alternatively, if it sits there
                    389: long enough, it will be shut down and released.
                    390: 
1.3       albertel  391: =cut
1.1       foxr      392: 
                    393: sub ServerToIdle {
                    394:     my $Socket   = shift;	# Get the socket.
1.49      foxr      395:     $KeyMode = $Socket->{AuthenticationMode};
1.7       foxr      396:     delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1       foxr      397: 
1.29      foxr      398:     &Debug(5, "Server to idle");
1.1       foxr      399: 
                    400:     #  If there's work to do, start the transaction:
                    401: 
1.23      foxr      402:     my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.29      foxr      403:     if ($reqdata ne undef)  {
                    404: 	Debug(5, "Queue gave request data: ".$reqdata->getRequest());
1.7       foxr      405: 	&StartRequest($Socket,  $reqdata);
1.8       foxr      406: 
1.1       foxr      407:     } else {
                    408: 	
                    409:     #  There's no work waiting, so push the server to idle list.
1.29      foxr      410: 	&Debug(5, "No new work requests, server connection going idle");
1.1       foxr      411: 	$IdleConnections->push($Socket);
                    412:     }
                    413: }
1.3       albertel  414: 
1.1       foxr      415: =pod
1.3       albertel  416: 
1.1       foxr      417: =head2 ClientWritable
1.3       albertel  418: 
                    419: Event callback for when a client socket is writable.
                    420: 
                    421: This callback is established when a transaction reponse is
                    422: avaiable from lond.  The response is forwarded to the unix socket
                    423: as it becomes writable in this sub.
                    424: 
1.1       foxr      425: Parameters:
                    426: 
1.3       albertel  427: =item Event
                    428: 
                    429: The event that has been triggered. Event->w->data is
                    430: the data and Event->w->fd is the socket to write.
1.1       foxr      431: 
                    432: =cut
1.3       albertel  433: 
1.1       foxr      434: sub ClientWritable {
                    435:     my $Event    = shift;
                    436:     my $Watcher  = $Event->w;
                    437:     my $Data     = $Watcher->data;
                    438:     my $Socket   = $Watcher->fd;
                    439: 
                    440:     # Try to send the data:
                    441: 
                    442:     &Debug(6, "ClientWritable writing".$Data);
                    443:     &Debug(9, "Socket is: ".$Socket);
                    444: 
1.6       foxr      445:     if($Socket->connected) {
                    446: 	my $result = $Socket->send($Data, 0);
                    447: 	
                    448: 	# $result undefined: the write failed.
                    449: 	# otherwise $result is the number of bytes written.
                    450: 	# Remove that preceding string from the data.
                    451: 	# If the resulting data is empty, destroy the watcher
                    452: 	# and set up a read event handler to accept the next
                    453: 	# request.
                    454: 	
                    455: 	&Debug(9,"Send result is ".$result." Defined: ".defined($result));
1.29      foxr      456: 	if($result ne undef) {
1.6       foxr      457: 	    &Debug(9, "send result was defined");
                    458: 	    if($result == length($Data)) { # Entire string sent.
                    459: 		&Debug(9, "ClientWritable data all written");
                    460: 		$Watcher->cancel();
                    461: 		#
                    462: 		#  Set up to read next request from socket:
                    463: 		
                    464: 		my $descr     = sprintf("Connection to lonc client %d",
                    465: 					$ActiveClients{$Socket});
                    466: 		Event->io(cb    => \&ClientRequest,
                    467: 			  poll  => 'r',
                    468: 			  desc  => $descr,
                    469: 			  data  => "",
                    470: 			  fd    => $Socket);
                    471: 		
                    472: 	    } else {		# Partial string sent.
                    473: 		$Watcher->data(substr($Data, $result));
1.15      foxr      474: 		if($result == 0) {    # client hung up on us!!
                    475: 		    Log("INFO", "lonc pipe client hung up on us!");
                    476: 		    $Watcher->cancel;
                    477: 		    $Socket->shutdown(2);
                    478: 		    $Socket->close();
                    479: 		}
1.6       foxr      480: 	    }
                    481: 	    
                    482: 	} else {			# Error of some sort...
                    483: 	    
                    484: 	    # Some errnos are possible:
                    485: 	    my $errno = $!;
                    486: 	    if($errno == POSIX::EWOULDBLOCK   ||
                    487: 	       $errno == POSIX::EAGAIN        ||
                    488: 	       $errno == POSIX::EINTR) {
                    489: 		# No action taken?
                    490: 	    } else {		# Unanticipated errno.
                    491: 		&Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
                    492: 		$Watcher->cancel;	# Stop the watcher.
                    493: 		$Socket->shutdown(2); # Kill connection
                    494: 		$Socket->close();	# Close the socket.
                    495: 	    }
1.1       foxr      496: 	    
                    497: 	}
1.6       foxr      498:     } else {
                    499: 	$Watcher->cancel();	# A delayed request...just cancel.
1.1       foxr      500:     }
                    501: }
                    502: 
                    503: =pod
1.3       albertel  504: 
1.1       foxr      505: =head2 CompleteTransaction
1.3       albertel  506: 
                    507: Called when the reply data has been received for a lond 
1.1       foxr      508: transaction.   The reply data must now be sent to the
                    509: ultimate client on the other end of the Unix socket.  This is
                    510: done by setting up a writable event for the socket with the
                    511: data the reply data.
1.3       albertel  512: 
1.1       foxr      513: Parameters:
1.3       albertel  514: 
                    515: =item Socket
                    516: 
                    517: Socket on which the lond transaction occured.  This is a
                    518: LondConnection. The data received is in the TransactionReply member.
                    519: 
1.7       foxr      520: =item Transaction
1.3       albertel  521: 
1.7       foxr      522: The transaction that is being completed.
1.1       foxr      523: 
                    524: =cut
1.3       albertel  525: 
1.1       foxr      526: sub CompleteTransaction {
1.29      foxr      527:     &Debug(5,"Complete transaction");
1.47      foxr      528: 
                    529:     my ($Socket, $Transaction) = @_;
1.1       foxr      530: 
1.7       foxr      531:     if (!$Transaction->isDeferred()) { # Normal transaction
                    532: 	my $data   = $Socket->GetReply(); # Data to send.
1.39      foxr      533: 	if($LogTransactions) {
                    534: 	    Log("SUCCESS", "Reply from lond: '$data'");
                    535: 	}
1.7       foxr      536: 	StartClientReply($Transaction, $data);
                    537:     } else {			# Delete deferred transaction file.
1.9       foxr      538: 	Log("SUCCESS", "A delayed transaction was completed");
1.23      foxr      539: 	LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
1.7       foxr      540: 	unlink $Transaction->getFile();
                    541:     }
1.6       foxr      542: }
1.42      foxr      543: 
1.6       foxr      544: =pod
1.42      foxr      545: 
1.6       foxr      546: =head1 StartClientReply
                    547: 
                    548:    Initiates a reply to a client where the reply data is a parameter.
                    549: 
1.7       foxr      550: =head2  parameters:
                    551: 
                    552: =item Transaction
                    553: 
                    554:     The transaction for which we are responding to the client.
                    555: 
                    556: =item data
                    557: 
                    558:     The data to send to apached client.
                    559: 
1.6       foxr      560: =cut
1.42      foxr      561: 
1.6       foxr      562: sub StartClientReply {
1.1       foxr      563: 
1.47      foxr      564:     my ($Transaction, $data) = @_;
1.12      foxr      565: 
1.7       foxr      566:     my $Client   = $Transaction->getClient();
                    567: 
1.1       foxr      568:     &Debug(8," Reply was: ".$data);
                    569:     my $Serial         = $ActiveClients{$Client};
                    570:     my $desc           = sprintf("Connection to lonc client %d",
                    571: 				 $Serial);
                    572:     Event->io(fd       => $Client,
                    573: 	      poll     => "w",
                    574: 	      desc     => $desc,
                    575: 	      cb       => \&ClientWritable,
                    576: 	      data     => $data);
                    577: }
1.42      foxr      578: 
1.4       foxr      579: =pod
1.42      foxr      580: 
1.4       foxr      581: =head2 FailTransaction
                    582: 
                    583:   Finishes a transaction with failure because the associated lond socket
1.7       foxr      584:   disconnected.  There are two possibilities:
                    585:   - The transaction is deferred: in which case we just quietly
                    586:     delete the transaction since there is no client connection.
                    587:   - The transaction is 'live' in which case we initiate the sending
                    588:     of "con_lost" to the client.
                    589: 
1.42      foxr      590: Deleting the transaction means killing it from the %ActiveTransactions hash.
1.4       foxr      591: 
                    592: Parameters:
                    593: 
                    594: =item client  
                    595:  
1.7       foxr      596:    The LondTransaction we are failing.
                    597:  
1.42      foxr      598: 
1.4       foxr      599: =cut
                    600: 
                    601: sub FailTransaction {
1.7       foxr      602:     my $transaction = shift;
1.17      foxr      603:     Log("WARNING", "Failing transaction ".$transaction->getRequest());
1.30      foxr      604:     Debug(1, "Failing transaction: ".$transaction->getRequest());
1.10      foxr      605:     if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11      foxr      606: 	my $client  = $transaction->getClient();
1.30      foxr      607: 	Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11      foxr      608: 	StartClientReply($transaction, "con_lost\n");
1.7       foxr      609:     }
1.4       foxr      610: 
                    611: }
                    612: 
                    613: =pod
1.6       foxr      614: =head1  EmptyQueue
1.7       foxr      615: 
1.6       foxr      616:   Fails all items in the work queue with con_lost.
1.7       foxr      617:   Note that each item in the work queue is a transaction.
                    618: 
1.6       foxr      619: =cut
                    620: sub EmptyQueue {
1.22      foxr      621:     $ConnectionRetriesLeft--;	# Counts as connection failure too.
1.6       foxr      622:     while($WorkQueue->Count()) {
1.10      foxr      623: 	my $request = $WorkQueue->dequeue(); # This is a transaction
1.7       foxr      624: 	FailTransaction($request);
1.6       foxr      625:     }
                    626: }
                    627: 
                    628: =pod
1.4       foxr      629: 
1.9       foxr      630: =head2 CloseAllLondConnections
                    631: 
                    632: Close all connections open on lond prior to exit e.g.
                    633: 
                    634: =cut
                    635: sub CloseAllLondConnections {
1.23      foxr      636:     foreach my $Socket (keys %ActiveConnections) {
1.42      foxr      637:       if(exists($ActiveTransactions{$Socket})) {
                    638: 	FailTransaction($ActiveTransactions{$Socket});
                    639:       }
                    640:       KillSocket($Socket);
1.9       foxr      641:     }
                    642: }
                    643: =cut
                    644: 
                    645: =pod
                    646: 
1.4       foxr      647: =head2 KillSocket
                    648:  
                    649: Destroys a socket.  This function can be called either when a socket
                    650: has died of 'natural' causes or because a socket needs to be pruned due to
                    651: idleness.  If the socket has died naturally, if there are no longer any 
                    652: live connections a new connection is created (in case there are transactions
                    653: in the queue).  If the socket has been pruned, it is never re-created.
                    654: 
                    655: Parameters:
1.1       foxr      656: 
1.4       foxr      657: =item Socket
                    658:  
                    659:   The socket to kill off.
                    660: 
                    661: =item Restart
                    662: 
                    663: nonzero if we are allowed to create a new connection.
                    664: 
                    665: 
                    666: =cut
                    667: sub KillSocket {
                    668:     my $Socket = shift;
                    669: 
1.17      foxr      670:     Log("WARNING", "Shutting down a socket");
1.9       foxr      671:     $Socket->Shutdown();
                    672: 
1.7       foxr      673:     #  If the socket came from the active connection set,
                    674:     #  delete its transaction... note that FailTransaction should
                    675:     #  already have been called!!!
                    676:     #  otherwise it came from the idle set.
                    677:     #  
1.4       foxr      678:     
                    679:     if(exists($ActiveTransactions{$Socket})) {
                    680: 	delete ($ActiveTransactions{$Socket});
                    681:     }
                    682:     if(exists($ActiveConnections{$Socket})) {
                    683: 	delete($ActiveConnections{$Socket});
1.37      albertel  684: 	$ConnectionCount--;
                    685: 	if ($ConnectionCount < 0) { $ConnectionCount = 0; }
1.4       foxr      686:     }
1.6       foxr      687:     #  If the connection count has gone to zero and there is work in the
                    688:     #  work queue, the work all gets failed with con_lost.
                    689:     #
                    690:     if($ConnectionCount == 0) {
1.22      foxr      691: 	EmptyQueue();
1.42      foxr      692: 	CloseAllLondConnections; # Should all already be closed but...
1.4       foxr      693:     }
                    694: }
1.1       foxr      695: 
                    696: =pod
1.3       albertel  697: 
1.1       foxr      698: =head2 LondReadable
1.3       albertel  699: 
1.1       foxr      700: This function is called whenever a lond connection
                    701: is readable.  The action is state dependent:
                    702: 
1.3       albertel  703: =head3 State=Initialized
                    704: 
                    705: We''re waiting for the challenge, this is a no-op until the
1.1       foxr      706: state changes.
1.3       albertel  707: 
1.1       foxr      708: =head3 State=Challenged 
1.3       albertel  709: 
                    710: The challenge has arrived we need to transition to Writable.
1.1       foxr      711: The connection must echo the challenge back.
1.3       albertel  712: 
1.1       foxr      713: =head3 State=ChallengeReplied
1.3       albertel  714: 
                    715: The challenge has been replied to.  The we are receiveing the 
1.1       foxr      716: 'ok' from the partner.
1.3       albertel  717: 
1.40      foxr      718: =head3  State=ReadingVersionString
                    719: 
                    720: We have requested the lond version and are reading the
                    721: version back.  Upon completion, we'll store the version away
                    722: for future use(?).
                    723: 
                    724: =head3 State=HostSet
                    725: 
                    726: We have selected the domain name of our peer (multhomed hosts)
                    727: and are getting the reply (presumably ok) back.
                    728: 
1.1       foxr      729: =head3 State=RequestingKey
1.3       albertel  730: 
                    731: The ok has been received and we need to send the request for
1.1       foxr      732: an encryption key.  Transition to writable for that.
1.3       albertel  733: 
1.1       foxr      734: =head3 State=ReceivingKey
1.3       albertel  735: 
                    736: The the key has been requested, now we are reading the new key.
                    737: 
1.1       foxr      738: =head3 State=Idle 
1.3       albertel  739: 
                    740: The encryption key has been negotiated or we have finished 
1.1       foxr      741: reading data from the a transaction.   If the callback data has
                    742: a client as well as the socket iformation, then we are 
                    743: doing a transaction and the data received is relayed to the client
                    744: before the socket is put on the idle list.
1.3       albertel  745: 
1.1       foxr      746: =head3 State=SendingRequest
1.3       albertel  747: 
                    748: I do not think this state can be received here, but if it is,
1.1       foxr      749: the appropriate thing to do is to transition to writable, and send
                    750: the request.
1.3       albertel  751: 
1.1       foxr      752: =head3 State=ReceivingReply
1.3       albertel  753: 
                    754: We finished sending the request to the server and now transition
1.1       foxr      755: to readable to receive the reply. 
                    756: 
                    757: The parameter to this function are:
1.3       albertel  758: 
1.1       foxr      759: The event. Implicit in this is the watcher and its data.  The data 
                    760: contains at least the lond connection object and, if a 
                    761: transaction is in progress, the socket attached to the local client.
                    762: 
1.3       albertel  763: =cut
1.1       foxr      764: 
                    765: sub LondReadable {
1.8       foxr      766: 
1.41      albertel  767:     my $Event      = shift;
                    768:     my $Watcher    = $Event->w;
                    769:     my $Socket     = $Watcher->data;
                    770:     my $client     = undef;
1.40      foxr      771: 
1.41      albertel  772:     &Debug(6,"LondReadable called state = ".$Socket->GetState());
1.40      foxr      773: 
                    774: 
1.41      albertel  775:     my $State = $Socket->GetState(); # All action depends on the state.
1.40      foxr      776: 
1.41      albertel  777:     SocketDump(6, $Socket);
                    778:     my $status = $Socket->Readable();
1.40      foxr      779: 
1.41      albertel  780:     &Debug(2, "Socket->Readable returned: $status");
1.40      foxr      781: 
1.41      albertel  782:     if($status != 0) {
                    783: 	# bad return from socket read. Currently this means that
                    784: 	# The socket has become disconnected. We fail the transaction.
1.40      foxr      785: 
1.41      albertel  786: 	Log("WARNING",
                    787: 	    "Lond connection lost.");
                    788: 	if(exists($ActiveTransactions{$Socket})) {
                    789: 	    FailTransaction($ActiveTransactions{$Socket});
                    790: 	}
                    791: 	$Watcher->cancel();
                    792: 	KillSocket($Socket);
                    793: 	$ConnectionRetriesLeft--;       # Counts as connection failure
                    794: 	return;
                    795:     }
                    796:     SocketDump(6,$Socket);
1.17      foxr      797: 
1.41      albertel  798:     $State = $Socket->GetState(); # Update in case of transition.
                    799:     &Debug(6, "After read, state is ".$State);
1.1       foxr      800: 
1.41      albertel  801:     if($State eq "Initialized") {
1.1       foxr      802: 
                    803: 
1.41      albertel  804:     } elsif ($State eq "ChallengeReceived") {
1.1       foxr      805: 	#  The challenge must be echoed back;  The state machine
                    806: 	# in the connection takes care of setting that up.  Just
                    807: 	# need to transition to writable:
1.41      albertel  808: 	
                    809: 	$Watcher->cb(\&LondWritable);
                    810: 	$Watcher->poll("w");
1.1       foxr      811: 
1.41      albertel  812:     } elsif ($State eq "ChallengeReplied") {
1.1       foxr      813: 
1.41      albertel  814:     } elsif ($State eq "RequestingVersion") {
                    815: 	# Need to ask for the version... that is writiability:
1.1       foxr      816: 
1.41      albertel  817: 	$Watcher->cb(\&LondWritable);
                    818: 	$Watcher->poll("w");
                    819: 
                    820:     } elsif ($State eq "ReadingVersionString") {
                    821: 	# Read the rest of the version string... 
                    822:     } elsif ($State eq "SetHost") {
                    823: 	# Need to request the actual domain get set...
                    824: 
                    825: 	$Watcher->cb(\&LondWritable);
                    826: 	$Watcher->poll("w");
                    827:     } elsif ($State eq "HostSet") {
                    828: 	# Reading the 'ok' from the peer.
                    829: 
                    830:     } elsif ($State eq "RequestingKey") {
1.1       foxr      831: 	#  The ok was received.  Now we need to request the key
                    832: 	#  That requires us to be writable:
                    833: 
1.41      albertel  834: 	$Watcher->cb(\&LondWritable);
                    835: 	$Watcher->poll("w");
1.1       foxr      836: 
1.41      albertel  837:     } elsif ($State eq "ReceivingKey") {
1.1       foxr      838: 
1.41      albertel  839:     } elsif ($State eq "Idle") {
1.40      foxr      840:    
1.41      albertel  841: 	# This is as good a spot as any to get the peer version
                    842: 	# string:
1.40      foxr      843:    
1.41      albertel  844: 	if($LondVersion eq "unknown") {
                    845: 	    $LondVersion = $Socket->PeerVersion();
                    846: 	    Log("INFO", "Connected to lond version: $LondVersion");
                    847: 	}
1.1       foxr      848: 	# If necessary, complete a transaction and then go into the
                    849: 	# idle queue.
1.22      foxr      850: 	#  Note that a trasition to idle indicates a live lond
                    851: 	# on the other end so reset the connection retries.
                    852: 	#
1.41      albertel  853: 	$ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
                    854: 	$Watcher->cancel();
                    855: 	if(exists($ActiveTransactions{$Socket})) {
                    856: 	    Debug(5,"Completing transaction!!");
                    857: 	    CompleteTransaction($Socket, 
                    858: 				$ActiveTransactions{$Socket});
                    859: 	} else {
                    860: 	    Log("SUCCESS", "Connection ".$ConnectionCount." to "
                    861: 		.$RemoteHost." now ready for action");
                    862: 	}
                    863: 	ServerToIdle($Socket);	# Next work unit or idle.
1.6       foxr      864: 	
1.41      albertel  865:     } elsif ($State eq "SendingRequest") {
1.1       foxr      866: 	#  We need to be writable for this and probably don't belong
                    867: 	#  here inthe first place.
                    868: 
1.41      albertel  869: 	Deubg(6, "SendingRequest state encountered in readable");
                    870: 	$Watcher->poll("w");
                    871: 	$Watcher->cb(\&LondWritable);
1.1       foxr      872: 
1.41      albertel  873:     } elsif ($State eq "ReceivingReply") {
1.1       foxr      874: 
                    875: 
1.41      albertel  876:     } else {
                    877: 	# Invalid state.
                    878: 	Debug(4, "Invalid state in LondReadable");
                    879:     }
1.1       foxr      880: }
1.3       albertel  881: 
1.1       foxr      882: =pod
1.3       albertel  883: 
1.1       foxr      884: =head2 LondWritable
1.3       albertel  885: 
1.1       foxr      886: This function is called whenever a lond connection
                    887: becomes writable while there is a writeable monitoring
                    888: event.  The action taken is very state dependent:
1.3       albertel  889: 
1.1       foxr      890: =head3 State = Connected 
1.3       albertel  891: 
                    892: The connection is in the process of sending the 'init' hailing to the
                    893: lond on the remote end.  The connection object''s Writable member is
                    894: called.  On error, ConnectionError is called to destroy the connection
                    895: and remove it from the ActiveConnections hash
                    896: 
1.1       foxr      897: =head3 Initialized
1.3       albertel  898: 
                    899: 'init' has been sent, writability monitoring is removed and
                    900: readability monitoring is started with LondReadable as the callback.
                    901: 
1.1       foxr      902: =head3 ChallengeReceived
1.3       albertel  903: 
                    904: The connection has received the who are you challenge from the remote
                    905: system, and is in the process of sending the challenge
                    906: response. Writable is called.
                    907: 
1.1       foxr      908: =head3 ChallengeReplied
1.3       albertel  909: 
                    910: The connection has replied to the initial challenge The we switch to
                    911: monitoring readability looking for the server to reply with 'ok'.
                    912: 
1.1       foxr      913: =head3 RequestingKey
1.3       albertel  914: 
                    915: The connection is in the process of requesting its encryption key.
                    916: Writable is called.
                    917: 
1.1       foxr      918: =head3 ReceivingKey
1.3       albertel  919: 
                    920: The connection has sent the request for a key.  Switch to readability
                    921: monitoring to accept the key
                    922: 
1.1       foxr      923: =head3 SendingRequest
1.3       albertel  924: 
                    925: The connection is in the process of sending a request to the server.
                    926: This request is part of a client transaction.  All the states until
                    927: now represent the client setup protocol. Writable is called.
                    928: 
1.1       foxr      929: =head3 ReceivingReply
                    930: 
1.3       albertel  931: The connection has sent a request.  Now it must receive a reply.
                    932: Readability monitoring is requested.
                    933: 
                    934: This function is an event handler and therefore receives as
1.1       foxr      935: a parameter the event that has fired.  The data for the watcher
                    936: of this event is a reference to a list of one or two elements,
                    937: depending on state. The first (and possibly only) element is the
                    938: socket.  The second (present only if a request is in progress)
                    939: is the socket on which to return a reply to the caller.
                    940: 
                    941: =cut
1.3       albertel  942: 
1.1       foxr      943: sub LondWritable {
                    944:     my $Event   = shift;
                    945:     my $Watcher = $Event->w;
1.8       foxr      946:     my $Socket  = $Watcher->data;
                    947:     my $State   = $Socket->GetState();
1.1       foxr      948: 
1.8       foxr      949:     Debug(6,"LondWritable State = ".$State."\n");
1.1       foxr      950: 
1.8       foxr      951:  
1.1       foxr      952:     #  Figure out what to do depending on the state of the socket:
                    953:     
                    954: 
                    955: 
                    956: 
                    957:     SocketDump(6,$Socket);
                    958: 
1.42      foxr      959:     #  If the socket is writable, we must always write.
                    960:     # Only by writing will we undergo state transitions.
                    961:     # Old logic wrote in state specific code below, however
                    962:     # That forces us at least through another invocation of
                    963:     # this function after writability is possible again.
                    964:     # This logic also factors out common code for handling
                    965:     # write failures... in all cases, write failures 
                    966:     # Kill the socket.
                    967:     #  This logic makes the branches of the >big< if below
                    968:     # so that the writing states are actually NO-OPs.
                    969: 
                    970:     if ($Socket->Writable() != 0) {
1.43      albertel  971: 	#  The write resulted in an error.
                    972: 	# We'll treat this as if the socket got disconnected:
                    973: 	Log("WARNING", "Connection to ".$RemoteHost.
                    974: 	    " has been disconnected");
                    975: 	if(exists($ActiveTransactions{$Socket})) {
                    976: 	    FailTransaction($ActiveTransactions{$Socket});
                    977: 	}
                    978: 	$Watcher->cancel();
                    979: 	KillSocket($Socket);
                    980: 	return;
1.42      foxr      981:     }
                    982: 
                    983: 
                    984: 
1.41      albertel  985:     if      ($State eq "Connected")         {
1.1       foxr      986: 
1.41      albertel  987: 	#  "init" is being sent...
1.42      foxr      988:  
1.41      albertel  989:     } elsif ($State eq "Initialized")       {
1.4       foxr      990: 
1.41      albertel  991: 	# Now that init was sent, we switch 
                    992: 	# to watching for readability:
1.1       foxr      993: 
1.41      albertel  994: 	$Watcher->cb(\&LondReadable);
                    995: 	$Watcher->poll("r");
                    996: 	
                    997:     } elsif ($State eq "ChallengeReceived") {
                    998: 	# We received the challenge, now we 
                    999: 	# are echoing it back. This is a no-op,
                   1000: 	# we're waiting for the state to change
1.1       foxr     1001: 	
1.41      albertel 1002:     } elsif ($State eq "ChallengeReplied")  {
                   1003: 	# The echo was sent back, so we switch
                   1004: 	# to watching readability.
                   1005: 
                   1006: 	$Watcher->cb(\&LondReadable);
                   1007: 	$Watcher->poll("r");
                   1008:     } elsif ($State eq "RequestingVersion") {
                   1009: 	# Sending the peer a version request...
1.42      foxr     1010: 
1.41      albertel 1011:     } elsif ($State eq "ReadingVersionString") {
                   1012: 	# Transition to read since we have sent the
                   1013: 	# version command and now just need to read the
                   1014: 	# version string from the peer:
1.40      foxr     1015:       
1.41      albertel 1016: 	$Watcher->cb(\&LondReadable);
                   1017: 	$Watcher->poll("r");
1.40      foxr     1018:       
1.41      albertel 1019:     } elsif ($State eq "SetHost") {
                   1020: 	#  Setting the remote domain...
1.42      foxr     1021: 
1.41      albertel 1022:     } elsif ($State eq "HostSet") {
                   1023: 	# Back to readable to get the ok.
1.40      foxr     1024:       
1.41      albertel 1025: 	$Watcher->cb(\&LondReadable);
                   1026: 	$Watcher->poll("r");
1.40      foxr     1027:       
                   1028: 
1.41      albertel 1029:     } elsif ($State eq "RequestingKey")     {
                   1030: 	# At this time we're requesting the key.
                   1031: 	# again, this is essentially a no-op.
                   1032: 
                   1033:     } elsif ($State eq "ReceivingKey")      {
                   1034: 	# Now we need to wait for the key
                   1035: 	# to come back from the peer:
                   1036: 
                   1037: 	$Watcher->cb(\&LondReadable);
                   1038: 	$Watcher->poll("r");
                   1039: 
                   1040:     } elsif ($State eq "SendingRequest")    {
1.40      foxr     1041:  
1.41      albertel 1042: 	# At this time we are sending a request to the
1.1       foxr     1043: 	# peer... write the next chunk:
                   1044: 
1.41      albertel 1045: 
                   1046:     } elsif ($State eq "ReceivingReply")    {
                   1047: 	# The send has completed.  Wait for the
                   1048: 	# data to come in for a reply.
                   1049: 	Debug(8,"Writable sent request/receiving reply");
                   1050: 	$Watcher->cb(\&LondReadable);
                   1051: 	$Watcher->poll("r");
1.1       foxr     1052: 
1.41      albertel 1053:     } else {
                   1054: 	#  Control only passes here on an error: 
                   1055: 	#  the socket state does not match any
                   1056: 	#  of the known states... so an error
                   1057: 	#  must be logged.
1.1       foxr     1058: 
1.41      albertel 1059: 	&Debug(4, "Invalid socket state ".$State."\n");
                   1060:     }
1.1       foxr     1061:     
                   1062: }
1.6       foxr     1063: =pod
                   1064:     
                   1065: =cut
                   1066: sub QueueDelayed {
1.8       foxr     1067:     Debug(3,"QueueDelayed called");
                   1068: 
1.6       foxr     1069:     my $path = "$perlvar{'lonSockDir'}/delayed";
1.8       foxr     1070: 
                   1071:     Debug(4, "Delayed path: ".$path);
1.6       foxr     1072:     opendir(DIRHANDLE, $path);
1.8       foxr     1073:     
1.23      foxr     1074:     my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1.6       foxr     1075:     closedir(DIRHANDLE);
                   1076:     my $dfname;
1.8       foxr     1077:     my $reqfile;
                   1078:     foreach $dfname (sort  @alldelayed) {
                   1079: 	$reqfile = "$path/$dfname";
                   1080: 	Debug(4, "queueing ".$reqfile);
1.6       foxr     1081: 	my $Handle = IO::File->new($reqfile);
                   1082: 	my $cmd    = <$Handle>;
1.8       foxr     1083: 	chomp $cmd;		# There may or may not be a newline...
1.12      foxr     1084: 	$cmd = $cmd."\n";	# now for sure there's exactly one newline.
1.7       foxr     1085: 	my $Transaction = LondTransaction->new($cmd);
                   1086: 	$Transaction->SetDeferred($reqfile);
                   1087: 	QueueTransaction($Transaction);
1.6       foxr     1088:     }
                   1089:     
                   1090: }
1.1       foxr     1091: 
                   1092: =pod
1.3       albertel 1093: 
1.1       foxr     1094: =head2 MakeLondConnection
1.3       albertel 1095: 
                   1096: Create a new lond connection object, and start it towards its initial
                   1097: idleness.  Once idle, it becomes elligible to receive transactions
                   1098: from the work queue.  If the work queue is not empty when the
                   1099: connection is completed and becomes idle, it will dequeue an entry and
                   1100: start off on it.
                   1101: 
1.1       foxr     1102: =cut
1.3       albertel 1103: 
1.1       foxr     1104: sub MakeLondConnection {     
                   1105:     Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
                   1106: 	  .GetServerPort());
                   1107: 
                   1108:     my $Connection = LondConnection->new(&GetServerHost(),
                   1109: 					 &GetServerPort());
                   1110: 
1.30      foxr     1111:     if($Connection eq undef) {	# Needs to be more robust later.
1.9       foxr     1112: 	Log("CRITICAL","Failed to make a connection with lond.");
1.10      foxr     1113: 	$ConnectionRetriesLeft--;
                   1114: 	return 0;		# Failure.
1.5       foxr     1115:     }  else {
1.22      foxr     1116: 
1.5       foxr     1117: 	# The connection needs to have writability 
                   1118: 	# monitored in order to send the init sequence
                   1119: 	# that starts the whole authentication/key
                   1120: 	# exchange underway.
                   1121: 	#
                   1122: 	my $Socket = $Connection->GetSocket();
1.30      foxr     1123: 	if($Socket eq undef) {
1.5       foxr     1124: 	    die "did not get a socket from the connection";
                   1125: 	} else {
                   1126: 	    &Debug(9,"MakeLondConnection got socket: ".$Socket);
                   1127: 	}
1.1       foxr     1128: 	
1.21      foxr     1129: 	$Connection->SetTimeoutCallback(\&SocketTimeout);
                   1130: 
1.23      foxr     1131: 	my $event = Event->io(fd       => $Socket,
1.5       foxr     1132: 			   poll     => 'w',
                   1133: 			   cb       => \&LondWritable,
1.8       foxr     1134: 			   data     => $Connection,
1.5       foxr     1135: 			   desc => 'Connection to lond server');
                   1136: 	$ActiveConnections{$Connection} = $event;
                   1137: 	
                   1138: 	$ConnectionCount++;
1.8       foxr     1139: 	Debug(4, "Connection count = ".$ConnectionCount);
1.6       foxr     1140: 	if($ConnectionCount == 1) { # First Connection:
                   1141: 	    QueueDelayed;
                   1142: 	}
1.9       foxr     1143: 	Log("SUCESS", "Created connection ".$ConnectionCount
                   1144: 	    ." to host ".GetServerHost());
1.10      foxr     1145: 	return 1;		# Return success.
1.1       foxr     1146:     }
                   1147:     
                   1148: }
1.3       albertel 1149: 
1.1       foxr     1150: =pod
1.3       albertel 1151: 
1.1       foxr     1152: =head2 StartRequest
1.3       albertel 1153: 
                   1154: Starts a lond request going on a specified lond connection.
                   1155: parameters are:
                   1156: 
                   1157: =item $Lond
                   1158: 
                   1159: Connection to the lond that will send the transaction and receive the
                   1160: reply.
                   1161: 
                   1162: =item $Client
                   1163: 
                   1164: Connection to the client that is making this request We got the
                   1165: request from this socket, and when the request has been relayed to
                   1166: lond and we get a reply back from lond it will get sent to this
                   1167: socket.
                   1168: 
                   1169: =item $Request
                   1170: 
                   1171: The text of the request to send.
                   1172: 
1.1       foxr     1173: =cut
                   1174: 
                   1175: sub StartRequest {
1.47      foxr     1176: 
                   1177:     my ($Lond, $Request) = @_;
1.1       foxr     1178:     
1.7       foxr     1179:     Debug(6, "StartRequest: ".$Request->getRequest());
1.1       foxr     1180: 
                   1181:     my $Socket = $Lond->GetSocket();
                   1182:     
1.7       foxr     1183:     $Request->Activate($Lond);
                   1184:     $ActiveTransactions{$Lond} = $Request;
1.1       foxr     1185: 
1.7       foxr     1186:     $Lond->InitiateTransaction($Request->getRequest());
1.23      foxr     1187:     my $event = Event->io(fd      => $Socket,
1.1       foxr     1188: 		       poll    => "w",
                   1189: 		       cb      => \&LondWritable,
                   1190: 		       data    => $Lond,
                   1191: 		       desc    => "lond transaction connection");
                   1192:     $ActiveConnections{$Lond} = $event;
                   1193:     Debug(8," Start Request made watcher data with ".$event->data."\n");
                   1194: }
                   1195: 
                   1196: =pod
1.3       albertel 1197: 
1.1       foxr     1198: =head2 QueueTransaction
1.3       albertel 1199: 
                   1200: If there is an idle lond connection, it is put to work doing this
                   1201: transaction.  Otherwise, the transaction is placed in the work queue.
                   1202: If placed in the work queue and the maximum number of connections has
                   1203: not yet been created, a new connection will be started.  Our goal is
                   1204: to eventually have a sufficient number of connections that the work
                   1205: queue will typically be empty.  parameters are:
                   1206: 
                   1207: =item Socket
                   1208: 
                   1209: open on the lonc client.
                   1210: 
                   1211: =item Request
                   1212: 
                   1213: data to send to the lond.
1.1       foxr     1214: 
                   1215: =cut
1.3       albertel 1216: 
1.1       foxr     1217: sub QueueTransaction {
                   1218: 
1.7       foxr     1219:     my $requestData   = shift;	# This is a LondTransaction.
                   1220:     my $cmd           = $requestData->getRequest();
                   1221: 
                   1222:     Debug(6,"QueueTransaction: ".$cmd);
1.1       foxr     1223: 
                   1224:     my $LondSocket    = $IdleConnections->pop();
                   1225:     if(!defined $LondSocket) {	# Need to queue request.
1.29      foxr     1226: 	Debug(5,"Must queue...");
1.1       foxr     1227: 	$WorkQueue->enqueue($requestData);
                   1228: 	if($ConnectionCount < $MaxConnectionCount) {
1.22      foxr     1229: 	    if($ConnectionRetriesLeft > 0) {
1.29      foxr     1230: 		Debug(5,"Starting additional lond connection");
1.22      foxr     1231: 		if(MakeLondConnection() == 0) {
                   1232: 		    EmptyQueue();	# Fail transactions, can't make connection.
1.42      foxr     1233: 		    CloseAllLondConnections; # Should all be closed but...
1.22      foxr     1234: 		}
                   1235: 	    } else {
                   1236: 		ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
                   1237: 		EmptyQueue();	# It's worse than that ... he's dead Jim.
1.42      foxr     1238: 		CloseAllLondConnections; # Should all be closed but..
1.17      foxr     1239: 	    }
1.1       foxr     1240: 	}
                   1241:     } else {			# Can start the request:
                   1242: 	Debug(8,"Can start...");
1.7       foxr     1243: 	StartRequest($LondSocket,  $requestData);
1.1       foxr     1244:     }
                   1245: }
                   1246: 
                   1247: #-------------------------- Lonc UNIX socket handling ---------------------
1.3       albertel 1248: 
1.1       foxr     1249: =pod
1.3       albertel 1250: 
1.1       foxr     1251: =head2 ClientRequest
1.3       albertel 1252: Callback that is called when data can be read from the UNIX domain
                   1253: socket connecting us with an apache server process.
1.1       foxr     1254: 
                   1255: =cut
                   1256: 
                   1257: sub ClientRequest {
                   1258:     Debug(6, "ClientRequest");
                   1259:     my $event   = shift;
                   1260:     my $watcher = $event->w;
                   1261:     my $socket  = $watcher->fd;
                   1262:     my $data    = $watcher->data;
                   1263:     my $thisread;
                   1264: 
                   1265:     Debug(9, "  Watcher named: ".$watcher->desc);
                   1266: 
                   1267:     my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
                   1268:     Debug(8, "rcv:  data length = ".length($thisread)
                   1269: 	  ." read =".$thisread);
1.29      foxr     1270:     unless (defined $rv  && length($thisread)) {
1.1       foxr     1271: 	 # Likely eof on socket.
                   1272: 	Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
                   1273: 	close($socket);
                   1274: 	$watcher->cancel();
                   1275: 	delete($ActiveClients{$socket});
1.10      foxr     1276: 	return;
1.1       foxr     1277:     }
                   1278:     Debug(8,"Data: ".$data." this read: ".$thisread);
                   1279:     $data = $data.$thisread;	# Append new data.
                   1280:     $watcher->data($data);
1.44      albertel 1281:     if($data =~ /\n$/) {	# Request entirely read.
1.10      foxr     1282: 	if($data eq "close_connection_exit\n") {
1.9       foxr     1283: 	    Log("CRITICAL",
                   1284: 		"Request Close Connection ... exiting");
                   1285: 	    CloseAllLondConnections();
                   1286: 	    exit;
                   1287: 	}
1.1       foxr     1288: 	Debug(8, "Complete transaction received: ".$data);
1.39      foxr     1289: 	if($LogTransactions) {
                   1290: 	    Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
                   1291: 	}
1.8       foxr     1292: 	my $Transaction = LondTransaction->new($data);
1.7       foxr     1293: 	$Transaction->SetClient($socket);
                   1294: 	QueueTransaction($Transaction);
1.1       foxr     1295: 	$watcher->cancel();	# Done looking for input data.
                   1296:     }
                   1297: 
                   1298: }
                   1299: 
                   1300: 
                   1301: =pod
1.3       albertel 1302: 
1.1       foxr     1303: =head2  NewClient
1.3       albertel 1304: 
                   1305: Callback that is called when a connection is received on the unix
                   1306: socket for a new client of lonc.  The callback is parameterized by the
                   1307: event.. which is a-priori assumed to be an io event, and therefore has
                   1308: an fd member that is the Listener socket.  We Accept the connection
                   1309: and register a new event on the readability of that socket:
                   1310: 
1.1       foxr     1311: =cut
1.3       albertel 1312: 
1.1       foxr     1313: sub NewClient {
                   1314:     Debug(6, "NewClient");
                   1315:     my $event      = shift;		# Get the event parameters.
                   1316:     my $watcher    = $event->w; 
                   1317:     my $socket     = $watcher->fd;	# Get the event' socket.
                   1318:     my $connection = $socket->accept();	# Accept the client connection.
                   1319:     Debug(8,"Connection request accepted from "
                   1320: 	  .GetPeername($connection, AF_UNIX));
                   1321: 
                   1322: 
                   1323:     my $description = sprintf("Connection to lonc client %d",
                   1324: 			      $ClientConnection);
                   1325:     Debug(9, "Creating event named: ".$description);
                   1326:     Event->io(cb      => \&ClientRequest,
                   1327: 	      poll    => 'r',
                   1328: 	      desc    => $description,
                   1329: 	      data    => "",
                   1330: 	      fd      => $connection);
                   1331:     $ActiveClients{$connection} = $ClientConnection;
                   1332:     $ClientConnection++;
                   1333: }
1.3       albertel 1334: 
                   1335: =pod
                   1336: 
                   1337: =head2 GetLoncSocketPath
                   1338: 
                   1339: Returns the name of the UNIX socket on which to listen for client
                   1340: connections.
1.1       foxr     1341: 
                   1342: =cut
1.3       albertel 1343: 
1.1       foxr     1344: sub GetLoncSocketPath {
                   1345:     return $UnixSocketDir."/".GetServerHost();
                   1346: }
                   1347: 
1.3       albertel 1348: =pod
                   1349: 
                   1350: =head2 GetServerHost
                   1351: 
                   1352: Returns the host whose lond we talk with.
                   1353: 
1.1       foxr     1354: =cut
1.3       albertel 1355: 
1.7       foxr     1356: sub GetServerHost {
1.1       foxr     1357:     return $RemoteHost;		# Setup by the fork.
                   1358: }
1.3       albertel 1359: 
                   1360: =pod
                   1361: 
                   1362: =head2 GetServerPort
                   1363: 
                   1364: Returns the lond port number.
                   1365: 
1.1       foxr     1366: =cut
1.3       albertel 1367: 
1.7       foxr     1368: sub GetServerPort {
1.1       foxr     1369:     return $perlvar{londPort};
                   1370: }
1.3       albertel 1371: 
                   1372: =pod
                   1373: 
                   1374: =head2 SetupLoncListener
                   1375: 
                   1376: Setup a lonc listener event.  The event is called when the socket
                   1377: becomes readable.. that corresponds to the receipt of a new
                   1378: connection.  The event handler established will accept the connection
                   1379: (creating a communcations channel), that int turn will establish
                   1380: another event handler to subess requests.
1.1       foxr     1381: 
                   1382: =cut
1.3       albertel 1383: 
1.1       foxr     1384: sub SetupLoncListener {
                   1385: 
                   1386:     my $socket;
                   1387:     my $SocketName = GetLoncSocketPath();
                   1388:     unlink($SocketName);
1.7       foxr     1389:     unless ($socket =IO::Socket::UNIX->new(Local  => $SocketName,
1.1       foxr     1390: 					    Listen => 10, 
                   1391: 					    Type   => SOCK_STREAM)) {
                   1392: 	die "Failed to create a lonc listner socket";
                   1393:     }
                   1394:     Event->io(cb     => \&NewClient,
                   1395: 	      poll   => 'r',
                   1396: 	      desc   => 'Lonc listener Unix Socket',
                   1397: 	      fd     => $socket);
                   1398: }
                   1399: 
1.39      foxr     1400: #
                   1401: #   Toggle transaction logging.
                   1402: #  Implicit inputs:  
                   1403: #     LogTransactions
                   1404: #  Implicit Outputs:
                   1405: #     LogTransactions
                   1406: sub ToggleTransactionLogging {
                   1407:     print STDERR "Toggle transaction logging...\n";
                   1408:     if(!$LogTransactions) {
                   1409: 	$LogTransactions = 1;
                   1410:     } else {
                   1411: 	$LogTransactions = 0;
                   1412:     }
                   1413: 
                   1414: 
                   1415:     Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
                   1416: }
                   1417: 
1.14      foxr     1418: =pod 
                   1419: 
                   1420: =head2 ChildStatus
                   1421:  
                   1422: Child USR1 signal handler to report the most recent status
                   1423: into the status file.
                   1424: 
1.22      foxr     1425: We also use this to reset the retries count in order to allow the
                   1426: client to retry connections with a previously dead server.
1.14      foxr     1427: =cut
1.46      albertel 1428: 
1.14      foxr     1429: sub ChildStatus {
                   1430:     my $event = shift;
                   1431:     my $watcher = $event->w;
                   1432: 
                   1433:     Debug(2, "Reporting child status because : ".$watcher->data);
                   1434:     my $docdir = $perlvar{'lonDocRoot'};
                   1435:     my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
                   1436:     print $fh $$."\t".$RemoteHost."\t".$Status."\t".
                   1437: 	$RecentLogEntry."\n";
1.38      foxr     1438:     #
                   1439:     #  Write out information about each of the connections:
                   1440:     #
1.46      albertel 1441:     if ($DebugLevel > 2) {
                   1442: 	print $fh "Active connection statuses: \n";
                   1443: 	my $i = 1;
                   1444: 	print STDERR  "================================= Socket Status Dump:\n";
                   1445: 	foreach my $item (keys %ActiveConnections) {
                   1446: 	    my $Socket = $ActiveConnections{$item}->data;
                   1447: 	    my $state  = $Socket->GetState();
                   1448: 	    print $fh "Connection $i State: $state\n";
                   1449: 	    print STDERR "---------------------- Connection $i \n";
1.48      foxr     1450: 	    $Socket->Dump(-1);	# Ensure it gets dumped..
1.46      albertel 1451: 	    $i++;	
                   1452: 	}
1.38      foxr     1453:     }
1.22      foxr     1454:     $ConnectionRetriesLeft = $ConnectionRetries;
1.14      foxr     1455: }
                   1456: 
1.1       foxr     1457: =pod
1.3       albertel 1458: 
1.10      foxr     1459: =head2 SignalledToDeath
                   1460: 
                   1461: Called in response to a signal that causes a chid process to die.
                   1462: 
                   1463: =cut
                   1464: 
                   1465: 
                   1466: sub SignalledToDeath {
1.14      foxr     1467:     my $event  = shift;
                   1468:     my $watcher= $event->w;
                   1469: 
                   1470:     Debug(2,"Signalled to death! via ".$watcher->data);
1.17      foxr     1471:     my ($signal) = $watcher->data;
1.10      foxr     1472:     chomp($signal);
                   1473:     Log("CRITICAL", "Abnormal exit.  Child $$ for $RemoteHost "
                   1474: 	."died through "."\"$signal\"");
                   1475:     LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
                   1476: 	    ."\"$signal\"");
1.12      foxr     1477:     exit 0;
1.10      foxr     1478: 
                   1479: }
1.16      foxr     1480: 
                   1481: =head2 ToggleDebug
                   1482: 
                   1483: This sub toggles trace debugging on and off.
                   1484: 
                   1485: =cut
                   1486: 
                   1487: sub ToggleDebug {
                   1488:     my $Current    = $DebugLevel;
                   1489:        $DebugLevel = $NextDebugLevel;
                   1490:        $NextDebugLevel = $Current;
                   1491: 
                   1492:     Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
                   1493: 
                   1494: }
                   1495: 
1.1       foxr     1496: =head2 ChildProcess
                   1497: 
                   1498: This sub implements a child process for a single lonc daemon.
                   1499: 
                   1500: =cut
                   1501: 
                   1502: sub ChildProcess {
                   1503: 
                   1504: 
1.14      foxr     1505:     #
                   1506:     #  Signals must be handled by the Event framework...
                   1507: #
                   1508: 
                   1509:     Event->signal(signal   => "QUIT",
                   1510: 		  cb       => \&SignalledToDeath,
                   1511: 		  data     => "QUIT");
                   1512:     Event->signal(signal   => "HUP",
                   1513: 		  cb       => \&ChildStatus,
                   1514: 		  data     => "HUP");
                   1515:     Event->signal(signal   => "USR1",
                   1516: 		  cb       => \&ChildStatus,
                   1517: 		  data     => "USR1");
1.39      foxr     1518:     Event->signal(signal   => "USR2",
                   1519: 		  cb       => \&ToggleTransactionLogging);
1.16      foxr     1520:     Event->signal(signal   => "INT",
                   1521: 		  cb       => \&ToggleDebug,
                   1522: 		  data     => "INT");
1.1       foxr     1523: 
                   1524:     SetupTimer();
                   1525:     
                   1526:     SetupLoncListener();
                   1527:     
                   1528:     $Event::Debuglevel = $DebugLevel;
                   1529:     
                   1530:     Debug(9, "Making initial lond connection for ".$RemoteHost);
                   1531: 
                   1532: # Setup the initial server connection:
                   1533:     
1.14      foxr     1534:      # &MakeLondConnection(); // let first work requirest do it.
1.10      foxr     1535: 
1.5       foxr     1536: 
1.1       foxr     1537:     Debug(9,"Entering event loop");
                   1538:     my $ret = Event::loop();		#  Start the main event loop.
                   1539:     
                   1540:     
                   1541:     die "Main event loop exited!!!";
                   1542: }
                   1543: 
                   1544: #  Create a new child for host passed in:
                   1545: 
                   1546: sub CreateChild {
1.12      foxr     1547:     my $sigset = POSIX::SigSet->new(SIGINT);
                   1548:     sigprocmask(SIG_BLOCK, $sigset);
1.1       foxr     1549:     my $host = shift;
                   1550:     $RemoteHost = $host;
1.9       foxr     1551:     Log("CRITICAL", "Forking server for ".$host);
1.23      foxr     1552:     my $pid          = fork;
1.1       foxr     1553:     if($pid) {			# Parent
1.17      foxr     1554: 	$RemoteHost = "Parent";
1.27      foxr     1555: 	$ChildHash{$pid} = $host;
1.26      foxr     1556: 	$HostToPid{$host}= $pid;
1.12      foxr     1557: 	sigprocmask(SIG_UNBLOCK, $sigset);
                   1558: 
1.1       foxr     1559:     } else {			# child.
1.5       foxr     1560: 	ShowStatus("Connected to ".$RemoteHost);
1.23      foxr     1561: 	$SIG{INT} = 'DEFAULT';
1.12      foxr     1562: 	sigprocmask(SIG_UNBLOCK, $sigset);
                   1563: 	ChildProcess;		# Does not return.
1.1       foxr     1564:     }
                   1565: 
                   1566: }
                   1567: #
                   1568: #  Parent process logic pass 1:
                   1569: #   For each entry in the hosts table, we will
                   1570: #  fork off an instance of ChildProcess to service the transactions
                   1571: #  to that host.  Each pid will be entered in a global hash
                   1572: #  with the value of the key, the host.
                   1573: #  The parent will then enter a loop to wait for process exits.
                   1574: #  Each exit gets logged and the child gets restarted.
                   1575: #
                   1576: 
1.5       foxr     1577: #
                   1578: #   Fork and start in new session so hang-up isn't going to 
                   1579: #   happen without intent.
                   1580: #
                   1581: 
                   1582: 
1.6       foxr     1583: 
                   1584: 
1.8       foxr     1585: 
1.6       foxr     1586: 
                   1587: ShowStatus("Forming new session");
                   1588: my $childpid = fork;
                   1589: if ($childpid != 0) {
                   1590:     sleep 4;			# Give child a chacne to break to
                   1591:     exit 0;			# a new sesion.
                   1592: }
1.8       foxr     1593: #
                   1594: #   Write my pid into the pid file so I can be located
                   1595: #
                   1596: 
                   1597: ShowStatus("Parent writing pid file:");
1.23      foxr     1598: my $execdir = $perlvar{'lonDaemons'};
1.8       foxr     1599: open (PIDSAVE, ">$execdir/logs/lonc.pid");
                   1600: print PIDSAVE "$$\n";
                   1601: close(PIDSAVE);
1.6       foxr     1602: 
1.17      foxr     1603: 
                   1604: 
1.6       foxr     1605: if (POSIX::setsid() < 0) {
                   1606:     print "Could not create new session\n";
                   1607:     exit -1;
                   1608: }
1.5       foxr     1609: 
                   1610: ShowStatus("Forking node servers");
                   1611: 
1.9       foxr     1612: Log("CRITICAL", "--------------- Starting children ---------------");
                   1613: 
1.31      foxr     1614: LondConnection::ReadConfig;               # Read standard config files.
1.1       foxr     1615: my $HostIterator = LondConnection::GetHostIterator;
                   1616: while (! $HostIterator->end()) {
                   1617: 
1.23      foxr     1618:     my $hostentryref = $HostIterator->get();
1.1       foxr     1619:     CreateChild($hostentryref->[0]);
1.26      foxr     1620:     $HostHash{$hostentryref->[0]} = $hostentryref->[4];
1.1       foxr     1621:     $HostIterator->next();
                   1622: }
1.12      foxr     1623: $RemoteHost = "Parent Server";
1.1       foxr     1624: 
                   1625: # Maintain the population:
1.5       foxr     1626: 
                   1627: ShowStatus("Parent keeping the flock");
1.1       foxr     1628: 
1.10      foxr     1629: #
                   1630: #   Set up parent signals:
                   1631: #
1.12      foxr     1632: 
1.14      foxr     1633: $SIG{INT}  = \&Terminate;
                   1634: $SIG{TERM} = \&Terminate; 
1.13      foxr     1635: $SIG{HUP}  = \&Restart;
1.14      foxr     1636: $SIG{USR1} = \&CheckKids; 
1.24      foxr     1637: $SIG{USR2} = \&UpdateKids;	# LonManage update request.
1.10      foxr     1638: 
1.1       foxr     1639: while(1) {
1.23      foxr     1640:     my $deadchild = wait();
1.1       foxr     1641:     if(exists $ChildHash{$deadchild}) {	# need to restart.
1.23      foxr     1642: 	my $deadhost = $ChildHash{$deadchild};
1.26      foxr     1643: 	delete($HostToPid{$deadhost});
1.1       foxr     1644: 	delete($ChildHash{$deadchild});
1.9       foxr     1645: 	Log("WARNING","Lost child pid= ".$deadchild.
1.1       foxr     1646: 	      "Connected to host ".$deadhost);
1.9       foxr     1647: 	Log("INFO", "Restarting child procesing ".$deadhost);
1.1       foxr     1648: 	CreateChild($deadhost);
                   1649:     }
1.13      foxr     1650: }
                   1651: 
1.14      foxr     1652: 
                   1653: 
                   1654: =pod
                   1655: 
                   1656: =head1 CheckKids
                   1657: 
                   1658:   Since kids do not die as easily in this implementation
                   1659: as the previous one, there  is no need to restart the
                   1660: dead ones (all dead kids get restarted when they die!!)
                   1661: The only thing this function does is to pass USR1 to the
                   1662: kids so that they report their status.
                   1663: 
                   1664: =cut
                   1665: 
                   1666: sub CheckKids {
                   1667:     Debug(2, "Checking status of children");
                   1668:     my $docdir = $perlvar{'lonDocRoot'};
                   1669:     my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
                   1670:     my $now=time;
                   1671:     my $local=localtime($now);
                   1672:     print $fh "LONC status $local - parent $$ \n\n";
1.23      foxr     1673:     foreach my $pid (keys %ChildHash) {
1.14      foxr     1674: 	Debug(2, "Sending USR1 -> $pid");
                   1675: 	kill 'USR1' => $pid;	# Tell Child to report status.
                   1676: 	sleep 1;		# Wait so file doesn't intermix.
                   1677:     }
                   1678: }
1.24      foxr     1679: 
                   1680: =pod
                   1681: 
                   1682: =head1  UpdateKids
                   1683: 
1.25      foxr     1684: parent's SIGUSR2 handler.  This handler:
1.24      foxr     1685: 
                   1686: =item
                   1687: 
                   1688: Rereads the hosts file.
                   1689: 
                   1690: =item
                   1691:  
                   1692: Kills off (via sigint) children for hosts that have disappeared.
                   1693: 
                   1694: =item
                   1695: 
1.27      foxr     1696: QUITs  children for hosts that already exist (this just forces a status display
1.24      foxr     1697: and resets the connection retry count for that host.
                   1698: 
                   1699: =item
                   1700: 
                   1701: Starts new children for hosts that have been added to the hosts.tab file since
                   1702: the start of the master program and maintains them.
                   1703: 
                   1704: =cut
                   1705: 
                   1706: sub UpdateKids {
1.27      foxr     1707: 
1.25      foxr     1708:     Log("INFO", "Updating connections via SIGUSR2");
1.27      foxr     1709: 
                   1710:     #  Just in case we need to kill our own lonc, we wait a few seconds to
                   1711:     #  give it a chance to receive and relay lond's response to the 
                   1712:     #  re-init command.
                   1713:     #
                   1714: 
                   1715:     sleep(2);			# Wait a couple of seconds.
                   1716: 
                   1717:     my %hosts;                   # Indexed by loncapa hostname, value=ip.
                   1718:     
                   1719:     # Need to re-read  the host table:
                   1720:     
                   1721:     
                   1722:     LondConnection::ReadConfig();
                   1723:     my $I = LondConnection::GetHostIterator;
                   1724:     while (! $I->end()) {
                   1725: 	my $item = $I->get();
                   1726: 	$hosts{$item->[0]} = $item->[4];
                   1727: 	$I->next();
                   1728:     }
                   1729: 
                   1730:     #  The logic below is written for clarity not for efficiency.
                   1731:     #  Since I anticipate that this function is only rarely called, that's
                   1732:     #  appropriate.  There are certainly ways to combine the loops below,
                   1733:     #  and anyone wishing to obscure the logic is welcome to go for it.
                   1734:     #  Note that we don't re-direct sigchild.  Instead we do what's needed
                   1735:     #  to the data structures that keep track of children to ensure that
                   1736:     #  when sigchild is honored, no new child is born.
                   1737:     #
                   1738: 
                   1739:     #  For each existing child; if it's host doesn't exist, kill the child.
                   1740: 
                   1741:     foreach my $child (keys %ChildHash) {
                   1742: 	my $oldhost = $ChildHash{$child};
                   1743: 	if (!(exists $hosts{$oldhost})) {
                   1744: 	    Log("CRITICAL", "Killing child for $oldhost  host no longer exists");
                   1745: 	    delete $ChildHash{$child};
                   1746: 	    delete $HostToPid{$oldhost};
                   1747: 	    kill 'QUIT' => $child;
                   1748: 	}
                   1749:     }
                   1750:     # For each remaining existing child; if it's host's ip has changed,
                   1751:     # Restart the child on the new IP.
                   1752: 
                   1753:     foreach my $child (keys %ChildHash) {
                   1754: 	my $oldhost = $ChildHash{$child};
                   1755: 	my $oldip   = $HostHash{$oldhost};
                   1756: 	if ($hosts{$oldhost} ne $oldip) {
                   1757: 
                   1758: 	    # kill the old child.
                   1759: 
                   1760: 	    Log("CRITICAL", "Killing child for $oldhost host ip has changed...");
                   1761: 	    delete $ChildHash{$child};
                   1762: 	    delete $HostToPid{$oldhost};
                   1763: 	    kill 'QUIT' => $child;
                   1764: 
                   1765: 	    # Do the book-keeping needed to start a new child on the
                   1766: 	    # new ip.
                   1767: 
                   1768: 	    $HostHash{$oldhost} = $hosts{$oldhost};
                   1769: 	    CreateChild($oldhost);
                   1770: 	}
                   1771:     }
                   1772:     # Finally, for each new host, not in the host hash, create a
                   1773:     # enter the host and create a new child.
                   1774:     # Force a status display of any existing process.
                   1775: 
                   1776:     foreach my $host (keys %hosts) {
                   1777: 	if(!(exists $HostHash{$host})) {
                   1778: 	    Log("INFO", "New host $host discovered in hosts.tab...");
                   1779: 	    $HostHash{$host} = $hosts{$host};
                   1780: 	    CreateChild($host);
                   1781: 	} else {
                   1782: 	    kill 'HUP' => $HostToPid{$host};    # status display.
                   1783: 	}
                   1784:     }
1.24      foxr     1785: }
                   1786: 
1.14      foxr     1787: 
1.13      foxr     1788: =pod
                   1789: 
                   1790: =head1 Restart
                   1791: 
                   1792: Signal handler for HUP... all children are killed and
                   1793: we self restart.  This is an el-cheapo way to re read
                   1794: the config file.
                   1795: 
                   1796: =cut
                   1797: 
                   1798: sub Restart {
1.23      foxr     1799:     &KillThemAll;		# First kill all the children.
1.13      foxr     1800:     Log("CRITICAL", "Restarting");
                   1801:     my $execdir = $perlvar{'lonDaemons'};
                   1802:     unlink("$execdir/logs/lonc.pid");
1.28      albertel 1803:     exec("$execdir/loncnew");
1.10      foxr     1804: }
1.12      foxr     1805: 
                   1806: =pod
                   1807: 
                   1808: =head1 KillThemAll
                   1809: 
                   1810: Signal handler that kills all children by sending them a 
1.17      foxr     1811: SIGHUP.  Responds to sigint and sigterm.
1.12      foxr     1812: 
                   1813: =cut
                   1814: 
1.10      foxr     1815: sub KillThemAll {
1.12      foxr     1816:     Debug(2, "Kill them all!!");
                   1817:     local($SIG{CHLD}) = 'IGNORE';      # Our children >will< die.
1.23      foxr     1818:     foreach my $pid (keys %ChildHash) {
1.12      foxr     1819: 	my $serving = $ChildHash{$pid};
                   1820: 	Debug(2, "Killing lonc for $serving pid = $pid");
                   1821: 	ShowStatus("Killing lonc for $serving pid = $pid");
                   1822: 	Log("CRITICAL", "Killing lonc for $serving pid = $pid");
1.17      foxr     1823: 	kill 'QUIT' => $pid;
                   1824: 	delete($ChildHash{$pid});
1.12      foxr     1825:     }
1.14      foxr     1826:     my $execdir = $perlvar{'lonDaemons'};
                   1827:     unlink("$execdir/logs/lonc.pid");
1.17      foxr     1828: 
1.1       foxr     1829: }
1.12      foxr     1830: 
1.14      foxr     1831: =pod
                   1832: 
                   1833: =head1 Terminate
                   1834:  
                   1835: Terminate the system.
                   1836: 
                   1837: =cut
                   1838: 
                   1839: sub Terminate {
                   1840:     KillThemAll;
1.17      foxr     1841:     Log("CRITICAL","Master process exiting");
                   1842:     exit 0;
1.14      foxr     1843: 
                   1844: }
1.12      foxr     1845: =pod
1.1       foxr     1846: 
                   1847: =head1 Theory
1.3       albertel 1848: 
                   1849: The event class is used to build this as a single process with an
                   1850: event driven model.  The following events are handled:
1.1       foxr     1851: 
                   1852: =item UNIX Socket connection Received
                   1853: 
                   1854: =item Request data arrives on UNIX data transfer socket.
                   1855: 
                   1856: =item lond connection becomes writable.
                   1857: 
                   1858: =item timer fires at 1 second intervals.
                   1859: 
                   1860: All sockets are run in non-blocking mode.  Timeouts managed by the timer
                   1861: handler prevents hung connections.
                   1862: 
                   1863: Key data structures:
                   1864: 
1.3       albertel 1865: =item RequestQueue
                   1866: 
                   1867: A queue of requests received from UNIX sockets that are
                   1868: waiting for a chance to be forwarded on a lond connection socket.
                   1869: 
                   1870: =item ActiveConnections
                   1871: 
                   1872: A hash of lond connections that have transactions in process that are
                   1873: available to be timed out.
                   1874: 
                   1875: =item ActiveTransactions
                   1876: 
                   1877: A hash indexed by lond connections that contain the client reply
                   1878: socket for each connection that has an active transaction on it.
                   1879: 
                   1880: =item IdleConnections
                   1881: 
                   1882: A hash of lond connections that have no work to do.  These connections
                   1883: can be closed if they are idle for a long enough time.
1.1       foxr     1884: 
                   1885: =cut

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