1: #!/usr/bin/perl
2: # The LearningOnline Network with CAPA
3: # lonc maintains the connections to remote computers
4: #
5: # $Id: loncnew,v 1.20 2003/08/25 18:48:11 albertel Exp $
6: #
7: # Copyright Michigan State University Board of Trustees
8: #
9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
10: ## LON-CAPA is free software; you can redistribute it and/or modify
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: #
28: #
29: # new lonc handles n request out bver m connections to londs.
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).
36: # - Add general logic for dispatching requests and timeouts. (done).
37: # - Add support for the lonc/lond requests. (done).
38: # - Add logging/status monitoring.
39: # - Add Signal handling - HUP restarts. USR1 status report.
40: # - Add Configuration file I/O (done).
41: # - Add management/status request interface.
42: # - Add deferred request capability. (done)
43: # - Detect transmission timeouts.
44: #
45:
46: # Change log:
47: # $Log: loncnew,v $
48: # Revision 1.20 2003/08/25 18:48:11 albertel
49: # - fixing a forgotten ;
50: #
51: # Revision 1.19 2003/08/19 09:31:46 foxr
52: # Get socket directory from configuration rather than the old hard coded test
53: # way that I forgot to un-hard code.
54: #
55: # Revision 1.18 2003/08/06 09:52:29 foxr
56: # Also needed to remember to fail in-flight transactions if their sends fail.
57: #
58: # Revision 1.17 2003/08/03 00:44:31 foxr
59: # 1. Correct handling of connection failure: Assume it means the host is
60: # unreachable and fail all of the queued transactions. Note that the
61: # inflight transactions should fail on their own time due either to timeout
62: # or send/receive failures.
63: # 2. Correct handling of logs for forced death signals. Pull the signal
64: # from the event watcher.
65: #
66: # Revision 1.16 2003/07/29 02:33:05 foxr
67: # Add SIGINT processing to child processes to toggle annoying trace mode
68: # on/off.. will try to use this to isolate the compute boud process issue.
69: #
70: # Revision 1.15 2003/07/15 02:07:05 foxr
71: # Added code for lonc/lond transaction timeouts. Who knows if it works right.
72: # The intent is for a timeout to fail any transaction in progress and kill
73: # off the sockt that timed out.
74: #
75: # Revision 1.14 2003/07/03 02:10:18 foxr
76: # Get all of the signals to work correctly.
77: #
78: # Revision 1.13 2003/07/02 01:31:55 foxr
79: # Added kill -HUP logic (restart).
80: #
81: # Revision 1.11 2003/06/25 01:54:44 foxr
82: # Fix more problems with transaction failure.
83: #
84: # Revision 1.10 2003/06/24 02:46:04 foxr
85: # Put a limit on the number of times we'll retry a connection.
86: # Start getting the signal stuff put in as well...note that need to get signals
87: # going or else 6the client will permanently give up on dead servers.
88: #
89: # Revision 1.9 2003/06/13 02:38:43 foxr
90: # Add logging in 'expected format'
91: #
92: # Revision 1.8 2003/06/11 02:04:35 foxr
93: # Support delayed transactions... this is done uniformly by encapsulating
94: # transactions in an object ... a LondTransaction that is implemented by
95: # LondTransaction.pm
96: #
97: # Revision 1.7 2003/06/03 01:59:39 foxr
98: # complete coding to support deferred transactions.
99: #
100: #
101:
102: use lib "/home/httpd/lib/perl/";
103: use lib "/home/foxr/newloncapa/types";
104: use Event qw(:DEFAULT );
105: use POSIX qw(:signal_h);
106: use POSIX;
107: use IO::Socket;
108: use IO::Socket::INET;
109: use IO::Socket::UNIX;
110: use IO::File;
111: use IO::Handle;
112: use Socket;
113: use Crypt::IDEA;
114: use LONCAPA::Queue;
115: use LONCAPA::Stack;
116: use LONCAPA::LondConnection;
117: use LONCAPA::LondTransaction;
118: use LONCAPA::Configuration;
119: use LONCAPA::HashIterator;
120:
121:
122: #
123: # Disable all signals we might receive from outside for now.
124: #
125: #$SIG{QUIT} = IGNORE;
126: #$SIG{HUP} = IGNORE;
127: #$SIG{USR1} = IGNORE;
128: #$SIG{INT} = IGNORE;
129: #$SIG{CHLD} = IGNORE;
130: #$SIG{__DIE__} = IGNORE;
131:
132:
133: # Read the httpd configuration file to get perl variables
134: # normally set in apache modules:
135:
136: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
137: my %perlvar = %{$perlvarref};
138:
139: #
140: # parent and shared variables.
141:
142: my %ChildHash; # by pid -> host.
143:
144:
145: my $MaxConnectionCount = 10; # Will get from config later.
146: my $ClientConnection = 0; # Uniquifier for client events.
147:
148: my $DebugLevel = 0;
149: my $NextDebugLevel= 10; # So Sigint can toggle this.
150: my $IdleTimeout= 3600; # Wait an hour before pruning connections.
151:
152: #
153: # The variables below are only used by the child processes.
154: #
155: my $RemoteHost; # Name of host child is talking to.
156: my $UnixSocketDir= $perlvar{'lonSockDir'};
157: my $IdleConnections = Stack->new(); # Set of idle connections
158: my %ActiveConnections; # Connections to the remote lond.
159: my %ActiveTransactions; # LondTransactions in flight.
160: my %ActiveClients; # Serial numbers of active clients by socket.
161: my $WorkQueue = Queue->new(); # Queue of pending transactions.
162: my $ConnectionCount = 0;
163: my $IdleSeconds = 0; # Number of seconds idle.
164: my $Status = ""; # Current status string.
165: my $RecentLogEntry = "";
166: my $ConnectionRetries=5; # Number of connection retries allowed.
167: my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
168:
169: #
170: # The hash below gives the HTML format for log messages
171: # given a severity.
172: #
173: my %LogFormats;
174:
175: $LogFormats{"CRITICAL"} = "<font color=red>CRITICAL: %s</font>";
176: $LogFormats{"SUCCESS"} = "<font color=green>SUCCESS: %s</font>";
177: $LogFormats{"INFO"} = "<font color=yellow>INFO: %s</font>";
178: $LogFormats{"WARNING"} = "<font color=blue>WARNING: %s</font>";
179: $LogFormats{"DEFAULT"} = " %s ";
180:
181:
182:
183: =pod
184:
185: =head2 LogPerm
186:
187: Makes an entry into the permanent log file.
188:
189: =cut
190: sub LogPerm {
191: my $message=shift;
192: my $execdir=$perlvar{'lonDaemons'};
193: my $now=time;
194: my $local=localtime($now);
195: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
196: print $fh "$now:$message:$local\n";
197: }
198:
199: =pod
200:
201: =head2 Log
202:
203: Logs a message to the log file.
204: Parameters:
205:
206: =item severity
207:
208: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
209: format string used to format the message. if the severity is
210: not a defined severity the Default format string is used.
211:
212: =item message
213:
214: The base message. In addtion to the format string, the message
215: will be appended to a string containing the name of our remote
216: host and the time will be formatted into the message.
217:
218: =cut
219:
220: sub Log {
221: my $severity = shift;
222: my $message = shift;
223:
224: if(!$LogFormats{$severity}) {
225: $severity = "DEFAULT";
226: }
227:
228: my $format = $LogFormats{$severity};
229:
230: # Put the window dressing in in front of the message format:
231:
232: my $now = time;
233: my $local = localtime($now);
234: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
235: my $finalformat = $finalformat.$format."\n";
236:
237: # open the file and put the result.
238:
239: my $execdir = $perlvar{'lonDaemons'};
240: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
241: my $msg = sprintf($finalformat, $message);
242: $RecentLogEntry = $msg;
243: print $fh $msg;
244:
245:
246: }
247:
248:
249: =pod
250:
251: =head2 GetPeerName
252:
253: Returns the name of the host that a socket object is connected to.
254:
255: =cut
256:
257: sub GetPeername {
258: my $connection = shift;
259: my $AdrFamily = shift;
260: my $peer = $connection->peername();
261: my $peerport;
262: my $peerip;
263: if($AdrFamily == AF_INET) {
264: ($peerport, $peerip) = sockaddr_in($peer);
265: my $peername = gethostbyaddr($iaddr, $AdrFamily);
266: return $peername;
267: } elsif ($AdrFamily == AF_UNIX) {
268: my $peerfile;
269: ($peerfile) = sockaddr_un($peer);
270: return $peerfile;
271: }
272: }
273: #----------------------------- Timer management ------------------------
274: =pod
275:
276: =head2 Debug
277:
278: Invoked to issue a debug message.
279:
280: =cut
281:
282: sub Debug {
283: my $level = shift;
284: my $message = shift;
285: if ($level <= $DebugLevel) {
286: Log("INFO", "-Debug- $message host = $RemotHost");
287: }
288: }
289:
290: sub SocketDump {
291: my $level = shift;
292: my $socket= shift;
293: if($level <= $DebugLevel) {
294: $socket->Dump();
295: }
296: }
297:
298: =pod
299:
300: =head2 ShowStatus
301:
302: Place some text as our pid status.
303: and as what we return in a SIGUSR1
304:
305: =cut
306: sub ShowStatus {
307: my $state = shift;
308: my $now = time;
309: my $local = localtime($now);
310: $Status = $local.": ".$state;
311: $0='lonc: '.$state.' '.$local;
312: }
313:
314: =pod
315:
316: =head 2 SocketTimeout
317:
318: Called when an action on the socket times out. The socket is
319: destroyed and any active transaction is failed.
320:
321:
322: =cut
323: sub SocketTimeout {
324: my $Socket = shift;
325:
326: KillSocket($Socket);
327: }
328:
329: =pod
330:
331: =head2 Tick
332:
333: Invoked each timer tick.
334:
335: =cut
336:
337:
338: sub Tick {
339: my $client;
340: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount);
341:
342: # Is it time to prune connection count:
343:
344:
345: if($IdleConnections->Count() &&
346: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
347: $IdleSeconds++;
348: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
349: $Socket = $IdleConnections->pop();
350: KillSocket($Socket);
351: }
352: } else {
353: $IdleSeconds = 0; # Reset idle count if not idle.
354: }
355: #
356: # For each inflight transaction, tick down its timeout counter.
357: #
358: foreach $item (keys %ActiveTransactions) {
359: my $Socket = $ActiveTransactions{$item}->getServer();
360: $Socket->Tick();
361: }
362: # Do we have work in the queue, but no connections to service them?
363: # If so, try to make some new connections to get things going again.
364: #
365:
366: my $Requests = $WorkQueue->Count();
367: if (($ConnectionCount == 0) && ($Requests > 0)) {
368: if ($ConnectionRetriesLeft > 0) {
369: my $Connections = ($Requests <= $MaxConnectionCount) ?
370: $Requests : $MaxConnectionCount;
371: Debug(1,"Work but no connections, start ".$Connections." of them");
372: for ($i =0; $i < $Connections; $i++) {
373: MakeLondConnection();
374: }
375: } else {
376: Debug(1,"Work in queue, but gave up on connections..flushing\n");
377: EmptyQueue(); # Connections can't be established.
378: }
379:
380: }
381: }
382:
383: =pod
384:
385: =head2 SetupTimer
386:
387: Sets up a 1 per sec recurring timer event. The event handler is used to:
388:
389: =item
390:
391: Trigger timeouts on communications along active sockets.
392:
393: =item
394:
395: Trigger disconnections of idle sockets.
396:
397: =cut
398:
399: sub SetupTimer {
400: Debug(6, "SetupTimer");
401: Event->timer(interval => 1, debug => 1, cb => \&Tick );
402: }
403:
404: =pod
405:
406: =head2 ServerToIdle
407:
408: This function is called when a connection to the server is
409: ready for more work.
410:
411: If there is work in the Work queue the top element is dequeued
412: and the connection will start to work on it. If the work queue is
413: empty, the connection is pushed on the idle connection stack where
414: it will either get another work unit, or alternatively, if it sits there
415: long enough, it will be shut down and released.
416:
417: =cut
418:
419: sub ServerToIdle {
420: my $Socket = shift; # Get the socket.
421: delete($ActiveTransactions{$Socket}); # Server has no transaction
422:
423: &Debug(6, "Server to idle");
424:
425: # If there's work to do, start the transaction:
426:
427: $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
428: unless($reqdata eq undef) {
429: Debug(9, "Queue gave request data: ".$reqdata->getRequest());
430: &StartRequest($Socket, $reqdata);
431:
432: } else {
433:
434: # There's no work waiting, so push the server to idle list.
435: &Debug(8, "No new work requests, server connection going idle");
436: $IdleConnections->push($Socket);
437: }
438: }
439:
440: =pod
441:
442: =head2 ClientWritable
443:
444: Event callback for when a client socket is writable.
445:
446: This callback is established when a transaction reponse is
447: avaiable from lond. The response is forwarded to the unix socket
448: as it becomes writable in this sub.
449:
450: Parameters:
451:
452: =item Event
453:
454: The event that has been triggered. Event->w->data is
455: the data and Event->w->fd is the socket to write.
456:
457: =cut
458:
459: sub ClientWritable {
460: my $Event = shift;
461: my $Watcher = $Event->w;
462: my $Data = $Watcher->data;
463: my $Socket = $Watcher->fd;
464:
465: # Try to send the data:
466:
467: &Debug(6, "ClientWritable writing".$Data);
468: &Debug(9, "Socket is: ".$Socket);
469:
470: if($Socket->connected) {
471: my $result = $Socket->send($Data, 0);
472:
473: # $result undefined: the write failed.
474: # otherwise $result is the number of bytes written.
475: # Remove that preceding string from the data.
476: # If the resulting data is empty, destroy the watcher
477: # and set up a read event handler to accept the next
478: # request.
479:
480: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
481: if(defined($result)) {
482: &Debug(9, "send result was defined");
483: if($result == length($Data)) { # Entire string sent.
484: &Debug(9, "ClientWritable data all written");
485: $Watcher->cancel();
486: #
487: # Set up to read next request from socket:
488:
489: my $descr = sprintf("Connection to lonc client %d",
490: $ActiveClients{$Socket});
491: Event->io(cb => \&ClientRequest,
492: poll => 'r',
493: desc => $descr,
494: data => "",
495: fd => $Socket);
496:
497: } else { # Partial string sent.
498: $Watcher->data(substr($Data, $result));
499: if($result == 0) { # client hung up on us!!
500: Log("INFO", "lonc pipe client hung up on us!");
501: $Watcher->cancel;
502: $Socket->shutdown(2);
503: $Socket->close();
504: }
505: }
506:
507: } else { # Error of some sort...
508:
509: # Some errnos are possible:
510: my $errno = $!;
511: if($errno == POSIX::EWOULDBLOCK ||
512: $errno == POSIX::EAGAIN ||
513: $errno == POSIX::EINTR) {
514: # No action taken?
515: } else { # Unanticipated errno.
516: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
517: $Watcher->cancel; # Stop the watcher.
518: $Socket->shutdown(2); # Kill connection
519: $Socket->close(); # Close the socket.
520: }
521:
522: }
523: } else {
524: $Watcher->cancel(); # A delayed request...just cancel.
525: }
526: }
527:
528: =pod
529:
530: =head2 CompleteTransaction
531:
532: Called when the reply data has been received for a lond
533: transaction. The reply data must now be sent to the
534: ultimate client on the other end of the Unix socket. This is
535: done by setting up a writable event for the socket with the
536: data the reply data.
537:
538: Parameters:
539:
540: =item Socket
541:
542: Socket on which the lond transaction occured. This is a
543: LondConnection. The data received is in the TransactionReply member.
544:
545: =item Transaction
546:
547: The transaction that is being completed.
548:
549: =cut
550:
551: sub CompleteTransaction {
552: &Debug(6,"Complete transaction");
553: my $Socket = shift;
554: my $Transaction = shift;
555:
556: if (!$Transaction->isDeferred()) { # Normal transaction
557: my $data = $Socket->GetReply(); # Data to send.
558: StartClientReply($Transaction, $data);
559: } else { # Delete deferred transaction file.
560: Log("SUCCESS", "A delayed transaction was completed");
561: LogPerm("S:$Client:".$Transaction->getRequest());
562: unlink $Transaction->getFile();
563: }
564: }
565: =pod
566: =head1 StartClientReply
567:
568: Initiates a reply to a client where the reply data is a parameter.
569:
570: =head2 parameters:
571:
572: =item Transaction
573:
574: The transaction for which we are responding to the client.
575:
576: =item data
577:
578: The data to send to apached client.
579:
580: =cut
581: sub StartClientReply {
582: my $Transaction = shift;
583: my $data = shift;
584:
585:
586: my $Client = $Transaction->getClient();
587:
588: &Debug(8," Reply was: ".$data);
589: my $Serial = $ActiveClients{$Client};
590: my $desc = sprintf("Connection to lonc client %d",
591:
592: $Serial);
593: Event->io(fd => $Client,
594: poll => "w",
595: desc => $desc,
596: cb => \&ClientWritable,
597: data => $data);
598: }
599: =pod
600: =head2 FailTransaction
601:
602: Finishes a transaction with failure because the associated lond socket
603: disconnected. There are two possibilities:
604: - The transaction is deferred: in which case we just quietly
605: delete the transaction since there is no client connection.
606: - The transaction is 'live' in which case we initiate the sending
607: of "con_lost" to the client.
608:
609: Deleting the transaction means killing it from the
610: %ActiveTransactions hash.
611:
612: Parameters:
613:
614: =item client
615:
616: The LondTransaction we are failing.
617:
618: =cut
619:
620: sub FailTransaction {
621: my $transaction = shift;
622: Log("WARNING", "Failing transaction ".$transaction->getRequest());
623: Debug(1, "Failing transaction: ".$transaction->getRequest());
624: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
625: my $client = $transaction->getClient();
626: Debug(1," Replying con_lost to ".$transaction->getRequest());
627: StartClientReply($transaction, "con_lost\n");
628: }
629:
630: }
631:
632: =pod
633: =head1 EmptyQueue
634:
635: Fails all items in the work queue with con_lost.
636: Note that each item in the work queue is a transaction.
637:
638: =cut
639: sub EmptyQueue {
640: while($WorkQueue->Count()) {
641: my $request = $WorkQueue->dequeue(); # This is a transaction
642: FailTransaction($request);
643: }
644: }
645:
646: =pod
647:
648: =head2 CloseAllLondConnections
649:
650: Close all connections open on lond prior to exit e.g.
651:
652: =cut
653: sub CloseAllLondConnections {
654: foreach $Socket (keys %ActiveConnections) {
655: KillSocket($Socket);
656: }
657: }
658: =cut
659:
660: =pod
661:
662: =head2 KillSocket
663:
664: Destroys a socket. This function can be called either when a socket
665: has died of 'natural' causes or because a socket needs to be pruned due to
666: idleness. If the socket has died naturally, if there are no longer any
667: live connections a new connection is created (in case there are transactions
668: in the queue). If the socket has been pruned, it is never re-created.
669:
670: Parameters:
671:
672: =item Socket
673:
674: The socket to kill off.
675:
676: =item Restart
677:
678: nonzero if we are allowed to create a new connection.
679:
680:
681: =cut
682: sub KillSocket {
683: my $Socket = shift;
684:
685: Log("WARNING", "Shutting down a socket");
686: $Socket->Shutdown();
687:
688: # If the socket came from the active connection set,
689: # delete its transaction... note that FailTransaction should
690: # already have been called!!!
691: # otherwise it came from the idle set.
692: #
693:
694: if(exists($ActiveTransactions{$Socket})) {
695: delete ($ActiveTransactions{$Socket});
696: }
697: if(exists($ActiveConnections{$Socket})) {
698: delete($ActiveConnections{$Socket});
699: }
700: $ConnectionCount--;
701:
702: # If the connection count has gone to zero and there is work in the
703: # work queue, the work all gets failed with con_lost.
704: #
705: if($ConnectionCount == 0) {
706: EmptyQueue;
707: }
708: }
709:
710: =pod
711:
712: =head2 LondReadable
713:
714: This function is called whenever a lond connection
715: is readable. The action is state dependent:
716:
717: =head3 State=Initialized
718:
719: We''re waiting for the challenge, this is a no-op until the
720: state changes.
721:
722: =head3 State=Challenged
723:
724: The challenge has arrived we need to transition to Writable.
725: The connection must echo the challenge back.
726:
727: =head3 State=ChallengeReplied
728:
729: The challenge has been replied to. The we are receiveing the
730: 'ok' from the partner.
731:
732: =head3 State=RequestingKey
733:
734: The ok has been received and we need to send the request for
735: an encryption key. Transition to writable for that.
736:
737: =head3 State=ReceivingKey
738:
739: The the key has been requested, now we are reading the new key.
740:
741: =head3 State=Idle
742:
743: The encryption key has been negotiated or we have finished
744: reading data from the a transaction. If the callback data has
745: a client as well as the socket iformation, then we are
746: doing a transaction and the data received is relayed to the client
747: before the socket is put on the idle list.
748:
749: =head3 State=SendingRequest
750:
751: I do not think this state can be received here, but if it is,
752: the appropriate thing to do is to transition to writable, and send
753: the request.
754:
755: =head3 State=ReceivingReply
756:
757: We finished sending the request to the server and now transition
758: to readable to receive the reply.
759:
760: The parameter to this function are:
761:
762: The event. Implicit in this is the watcher and its data. The data
763: contains at least the lond connection object and, if a
764: transaction is in progress, the socket attached to the local client.
765:
766: =cut
767:
768: sub LondReadable {
769:
770: my $Event = shift;
771: my $Watcher = $Event->w;
772: my $Socket = $Watcher->data;
773: my $client = undef;
774:
775: &Debug(6,"LondReadable called state = ".$State);
776:
777:
778: my $State = $Socket->GetState(); # All action depends on the state.
779:
780: SocketDump(6, $Socket);
781: my $status = $Socket->Readable();
782:
783: &Debug(2, "Socket->Readable returned: $status");
784:
785: if($status != 0) {
786: # bad return from socket read. Currently this means that
787: # The socket has become disconnected. We fail the transaction.
788:
789: Log("WARNING",
790: "Lond connection lost.");
791: if(exists($ActiveTransactions{$Socket})) {
792: FailTransaction($ActiveTransactions{$Socket});
793: }
794: $Watcher->cancel();
795: KillSocket($Socket);
796: return;
797: }
798: SocketDump(6,$Socket);
799:
800: $State = $Socket->GetState(); # Update in case of transition.
801: &Debug(6, "After read, state is ".$State);
802:
803: if($State eq "Initialized") {
804:
805:
806: } elsif ($State eq "ChallengeReceived") {
807: # The challenge must be echoed back; The state machine
808: # in the connection takes care of setting that up. Just
809: # need to transition to writable:
810:
811: $Watcher->cb(\&LondWritable);
812: $Watcher->poll("w");
813:
814: } elsif ($State eq "ChallengeReplied") {
815:
816:
817: } elsif ($State eq "RequestingKey") {
818: # The ok was received. Now we need to request the key
819: # That requires us to be writable:
820:
821: $Watcher->cb(\&LondWritable);
822: $Watcher->poll("w");
823:
824: } elsif ($State eq "ReceivingKey") {
825:
826: } elsif ($State eq "Idle") {
827: # If necessary, complete a transaction and then go into the
828: # idle queue.
829: $Watcher->cancel();
830: if(exists($ActiveTransactions{$Socket})) {
831: Debug(8,"Completing transaction!!");
832: CompleteTransaction($Socket,
833: $ActiveTransactions{$Socket});
834: } else {
835: Log("SUCCESS", "Connection ".$ConnectionCount." to "
836: .$RemoteHost." now ready for action");
837: }
838: ServerToIdle($Socket); # Next work unit or idle.
839:
840: } elsif ($State eq "SendingRequest") {
841: # We need to be writable for this and probably don't belong
842: # here inthe first place.
843:
844: Deubg(6, "SendingRequest state encountered in readable");
845: $Watcher->poll("w");
846: $Watcher->cb(\&LondWritable);
847:
848: } elsif ($State eq "ReceivingReply") {
849:
850:
851: } else {
852: # Invalid state.
853: Debug(4, "Invalid state in LondReadable");
854: }
855: }
856:
857: =pod
858:
859: =head2 LondWritable
860:
861: This function is called whenever a lond connection
862: becomes writable while there is a writeable monitoring
863: event. The action taken is very state dependent:
864:
865: =head3 State = Connected
866:
867: The connection is in the process of sending the 'init' hailing to the
868: lond on the remote end. The connection object''s Writable member is
869: called. On error, ConnectionError is called to destroy the connection
870: and remove it from the ActiveConnections hash
871:
872: =head3 Initialized
873:
874: 'init' has been sent, writability monitoring is removed and
875: readability monitoring is started with LondReadable as the callback.
876:
877: =head3 ChallengeReceived
878:
879: The connection has received the who are you challenge from the remote
880: system, and is in the process of sending the challenge
881: response. Writable is called.
882:
883: =head3 ChallengeReplied
884:
885: The connection has replied to the initial challenge The we switch to
886: monitoring readability looking for the server to reply with 'ok'.
887:
888: =head3 RequestingKey
889:
890: The connection is in the process of requesting its encryption key.
891: Writable is called.
892:
893: =head3 ReceivingKey
894:
895: The connection has sent the request for a key. Switch to readability
896: monitoring to accept the key
897:
898: =head3 SendingRequest
899:
900: The connection is in the process of sending a request to the server.
901: This request is part of a client transaction. All the states until
902: now represent the client setup protocol. Writable is called.
903:
904: =head3 ReceivingReply
905:
906: The connection has sent a request. Now it must receive a reply.
907: Readability monitoring is requested.
908:
909: This function is an event handler and therefore receives as
910: a parameter the event that has fired. The data for the watcher
911: of this event is a reference to a list of one or two elements,
912: depending on state. The first (and possibly only) element is the
913: socket. The second (present only if a request is in progress)
914: is the socket on which to return a reply to the caller.
915:
916: =cut
917:
918: sub LondWritable {
919: my $Event = shift;
920: my $Watcher = $Event->w;
921: my $Socket = $Watcher->data;
922: my $State = $Socket->GetState();
923:
924: Debug(6,"LondWritable State = ".$State."\n");
925:
926:
927: # Figure out what to do depending on the state of the socket:
928:
929:
930:
931:
932: SocketDump(6,$Socket);
933:
934: if ($State eq "Connected") {
935:
936: if ($Socket->Writable() != 0) {
937: # The write resulted in an error.
938: # We'll treat this as if the socket got disconnected:
939: Log("WARNING", "Connection to ".$RemoteHost.
940: " has been disconnected");
941: FailTransaction($ActiveTransactions{$Socket});
942: $Watcher->cancel();
943: KillSocket($Socket);
944: return;
945: }
946: # "init" is being sent...
947:
948:
949: } elsif ($State eq "Initialized") {
950:
951: # Now that init was sent, we switch
952: # to watching for readability:
953:
954: $Watcher->cb(\&LondReadable);
955: $Watcher->poll("r");
956:
957: } elsif ($State eq "ChallengeReceived") {
958: # We received the challenge, now we
959: # are echoing it back. This is a no-op,
960: # we're waiting for the state to change
961:
962: if($Socket->Writable() != 0) {
963:
964: $Watcher->cancel();
965: KillSocket($Socket);
966: return;
967: }
968:
969: } elsif ($State eq "ChallengeReplied") {
970: # The echo was sent back, so we switch
971: # to watching readability.
972:
973: $Watcher->cb(\&LondReadable);
974: $Watcher->poll("r");
975:
976: } elsif ($State eq "RequestingKey") {
977: # At this time we're requesting the key.
978: # again, this is essentially a no-op.
979: # we'll write the next chunk until the
980: # state changes.
981:
982: if($Socket->Writable() != 0) {
983: # Write resulted in an error.
984:
985: $Watcher->cancel();
986: KillSocket($Socket);
987: return;
988:
989: }
990: } elsif ($State eq "ReceivingKey") {
991: # Now we need to wait for the key
992: # to come back from the peer:
993:
994: $Watcher->cb(\&LondReadable);
995: $Watcher->poll("r");
996:
997: } elsif ($State eq "SendingRequest") {
998: # At this time we are sending a request to the
999: # peer... write the next chunk:
1000:
1001: if($Socket->Writable() != 0) {
1002:
1003: if(exists($ActiveTransactions{$Socket})) {
1004: Debug(3, "Lond connection lost, failing transactions");
1005: FailTransaction($ActiveTransactions{$Socket});
1006: }
1007: $Watcher->cancel();
1008: KillSocket($Socket);
1009: return;
1010:
1011: }
1012:
1013: } elsif ($State eq "ReceivingReply") {
1014: # The send has completed. Wait for the
1015: # data to come in for a reply.
1016: Debug(8,"Writable sent request/receiving reply");
1017: $Watcher->cb(\&LondReadable);
1018: $Watcher->poll("r");
1019:
1020: } else {
1021: # Control only passes here on an error:
1022: # the socket state does not match any
1023: # of the known states... so an error
1024: # must be logged.
1025:
1026: &Debug(4, "Invalid socket state ".$State."\n");
1027: }
1028:
1029: }
1030: =pod
1031:
1032: =cut
1033: sub QueueDelayed {
1034: Debug(3,"QueueDelayed called");
1035:
1036: my $path = "$perlvar{'lonSockDir'}/delayed";
1037:
1038: Debug(4, "Delayed path: ".$path);
1039: opendir(DIRHANDLE, $path);
1040:
1041: @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1042: Debug(4, "Got ".$alldelayed." delayed files");
1043: closedir(DIRHANDLE);
1044: my $dfname;
1045: my $reqfile;
1046: foreach $dfname (sort @alldelayed) {
1047: $reqfile = "$path/$dfname";
1048: Debug(4, "queueing ".$reqfile);
1049: my $Handle = IO::File->new($reqfile);
1050: my $cmd = <$Handle>;
1051: chomp $cmd; # There may or may not be a newline...
1052: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1053: my $Transaction = LondTransaction->new($cmd);
1054: $Transaction->SetDeferred($reqfile);
1055: QueueTransaction($Transaction);
1056: }
1057:
1058: }
1059:
1060: =pod
1061:
1062: =head2 MakeLondConnection
1063:
1064: Create a new lond connection object, and start it towards its initial
1065: idleness. Once idle, it becomes elligible to receive transactions
1066: from the work queue. If the work queue is not empty when the
1067: connection is completed and becomes idle, it will dequeue an entry and
1068: start off on it.
1069:
1070: =cut
1071:
1072: sub MakeLondConnection {
1073: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1074: .GetServerPort());
1075:
1076: my $Connection = LondConnection->new(&GetServerHost(),
1077: &GetServerPort());
1078:
1079: if($Connection == undef) { # Needs to be more robust later.
1080: Log("CRITICAL","Failed to make a connection with lond.");
1081: $ConnectionRetriesLeft--;
1082: return 0; # Failure.
1083: } else {
1084: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
1085: # The connection needs to have writability
1086: # monitored in order to send the init sequence
1087: # that starts the whole authentication/key
1088: # exchange underway.
1089: #
1090: my $Socket = $Connection->GetSocket();
1091: if($Socket == undef) {
1092: die "did not get a socket from the connection";
1093: } else {
1094: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1095: }
1096:
1097:
1098: $event = Event->io(fd => $Socket,
1099: poll => 'w',
1100: cb => \&LondWritable,
1101: data => $Connection,
1102: desc => 'Connection to lond server');
1103: $ActiveConnections{$Connection} = $event;
1104:
1105: $ConnectionCount++;
1106: Debug(4, "Connection count = ".$ConnectionCount);
1107: if($ConnectionCount == 1) { # First Connection:
1108: QueueDelayed;
1109: }
1110: Log("SUCESS", "Created connection ".$ConnectionCount
1111: ." to host ".GetServerHost());
1112: return 1; # Return success.
1113: }
1114:
1115: }
1116:
1117: =pod
1118:
1119: =head2 StartRequest
1120:
1121: Starts a lond request going on a specified lond connection.
1122: parameters are:
1123:
1124: =item $Lond
1125:
1126: Connection to the lond that will send the transaction and receive the
1127: reply.
1128:
1129: =item $Client
1130:
1131: Connection to the client that is making this request We got the
1132: request from this socket, and when the request has been relayed to
1133: lond and we get a reply back from lond it will get sent to this
1134: socket.
1135:
1136: =item $Request
1137:
1138: The text of the request to send.
1139:
1140: =cut
1141:
1142: sub StartRequest {
1143: my $Lond = shift;
1144: my $Request = shift; # This is a LondTransaction.
1145:
1146: Debug(6, "StartRequest: ".$Request->getRequest());
1147:
1148: my $Socket = $Lond->GetSocket();
1149:
1150: $Request->Activate($Lond);
1151: $ActiveTransactions{$Lond} = $Request;
1152:
1153: $Lond->InitiateTransaction($Request->getRequest());
1154: $event = Event->io(fd => $Socket,
1155: poll => "w",
1156: cb => \&LondWritable,
1157: data => $Lond,
1158: desc => "lond transaction connection");
1159: $ActiveConnections{$Lond} = $event;
1160: Debug(8," Start Request made watcher data with ".$event->data."\n");
1161: }
1162:
1163: =pod
1164:
1165: =head2 QueueTransaction
1166:
1167: If there is an idle lond connection, it is put to work doing this
1168: transaction. Otherwise, the transaction is placed in the work queue.
1169: If placed in the work queue and the maximum number of connections has
1170: not yet been created, a new connection will be started. Our goal is
1171: to eventually have a sufficient number of connections that the work
1172: queue will typically be empty. parameters are:
1173:
1174: =item Socket
1175:
1176: open on the lonc client.
1177:
1178: =item Request
1179:
1180: data to send to the lond.
1181:
1182: =cut
1183:
1184: sub QueueTransaction {
1185:
1186: my $requestData = shift; # This is a LondTransaction.
1187: my $cmd = $requestData->getRequest();
1188:
1189: Debug(6,"QueueTransaction: ".$cmd);
1190:
1191: my $LondSocket = $IdleConnections->pop();
1192: if(!defined $LondSocket) { # Need to queue request.
1193: Debug(8,"Must queue...");
1194: $WorkQueue->enqueue($requestData);
1195: if($ConnectionCount < $MaxConnectionCount) {
1196: Debug(4,"Starting additional lond connection");
1197: if(MakeLondConnection() == 0) {
1198: EmptyQueue(); # Fail transactions, can't make connection.
1199: }
1200: }
1201: } else { # Can start the request:
1202: Debug(8,"Can start...");
1203: StartRequest($LondSocket, $requestData);
1204: }
1205: }
1206:
1207: #-------------------------- Lonc UNIX socket handling ---------------------
1208:
1209: =pod
1210:
1211: =head2 ClientRequest
1212: Callback that is called when data can be read from the UNIX domain
1213: socket connecting us with an apache server process.
1214:
1215: =cut
1216:
1217: sub ClientRequest {
1218: Debug(6, "ClientRequest");
1219: my $event = shift;
1220: my $watcher = $event->w;
1221: my $socket = $watcher->fd;
1222: my $data = $watcher->data;
1223: my $thisread;
1224:
1225: Debug(9, " Watcher named: ".$watcher->desc);
1226:
1227: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1228: Debug(8, "rcv: data length = ".length($thisread)
1229: ." read =".$thisread);
1230: unless (defined $rv && length($thisread)) {
1231: # Likely eof on socket.
1232: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1233: close($socket);
1234: $watcher->cancel();
1235: delete($ActiveClients{$socket});
1236: return;
1237: }
1238: Debug(8,"Data: ".$data." this read: ".$thisread);
1239: $data = $data.$thisread; # Append new data.
1240: $watcher->data($data);
1241: if($data =~ /(.*\n)/) { # Request entirely read.
1242: if($data eq "close_connection_exit\n") {
1243: Log("CRITICAL",
1244: "Request Close Connection ... exiting");
1245: CloseAllLondConnections();
1246: exit;
1247: }
1248: Debug(8, "Complete transaction received: ".$data);
1249: my $Transaction = LondTransaction->new($data);
1250: $Transaction->SetClient($socket);
1251: QueueTransaction($Transaction);
1252: $watcher->cancel(); # Done looking for input data.
1253: }
1254:
1255: }
1256:
1257:
1258: =pod
1259:
1260: =head2 NewClient
1261:
1262: Callback that is called when a connection is received on the unix
1263: socket for a new client of lonc. The callback is parameterized by the
1264: event.. which is a-priori assumed to be an io event, and therefore has
1265: an fd member that is the Listener socket. We Accept the connection
1266: and register a new event on the readability of that socket:
1267:
1268: =cut
1269:
1270: sub NewClient {
1271: Debug(6, "NewClient");
1272: my $event = shift; # Get the event parameters.
1273: my $watcher = $event->w;
1274: my $socket = $watcher->fd; # Get the event' socket.
1275: my $connection = $socket->accept(); # Accept the client connection.
1276: Debug(8,"Connection request accepted from "
1277: .GetPeername($connection, AF_UNIX));
1278:
1279:
1280: my $description = sprintf("Connection to lonc client %d",
1281: $ClientConnection);
1282: Debug(9, "Creating event named: ".$description);
1283: Event->io(cb => \&ClientRequest,
1284: poll => 'r',
1285: desc => $description,
1286: data => "",
1287: fd => $connection);
1288: $ActiveClients{$connection} = $ClientConnection;
1289: $ClientConnection++;
1290: }
1291:
1292: =pod
1293:
1294: =head2 GetLoncSocketPath
1295:
1296: Returns the name of the UNIX socket on which to listen for client
1297: connections.
1298:
1299: =cut
1300:
1301: sub GetLoncSocketPath {
1302: return $UnixSocketDir."/".GetServerHost();
1303: }
1304:
1305: =pod
1306:
1307: =head2 GetServerHost
1308:
1309: Returns the host whose lond we talk with.
1310:
1311: =cut
1312:
1313: sub GetServerHost {
1314: return $RemoteHost; # Setup by the fork.
1315: }
1316:
1317: =pod
1318:
1319: =head2 GetServerPort
1320:
1321: Returns the lond port number.
1322:
1323: =cut
1324:
1325: sub GetServerPort {
1326: return $perlvar{londPort};
1327: }
1328:
1329: =pod
1330:
1331: =head2 SetupLoncListener
1332:
1333: Setup a lonc listener event. The event is called when the socket
1334: becomes readable.. that corresponds to the receipt of a new
1335: connection. The event handler established will accept the connection
1336: (creating a communcations channel), that int turn will establish
1337: another event handler to subess requests.
1338:
1339: =cut
1340:
1341: sub SetupLoncListener {
1342:
1343: my $socket;
1344: my $SocketName = GetLoncSocketPath();
1345: unlink($SocketName);
1346: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1347: Listen => 10,
1348: Type => SOCK_STREAM)) {
1349: die "Failed to create a lonc listner socket";
1350: }
1351: Event->io(cb => \&NewClient,
1352: poll => 'r',
1353: desc => 'Lonc listener Unix Socket',
1354: fd => $socket);
1355: }
1356:
1357: =pod
1358:
1359: =head2 ChildStatus
1360:
1361: Child USR1 signal handler to report the most recent status
1362: into the status file.
1363:
1364: =cut
1365: sub ChildStatus {
1366: my $event = shift;
1367: my $watcher = $event->w;
1368:
1369: Debug(2, "Reporting child status because : ".$watcher->data);
1370: my $docdir = $perlvar{'lonDocRoot'};
1371: my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
1372: print $fh $$."\t".$RemoteHost."\t".$Status."\t".
1373: $RecentLogEntry."\n";
1374: }
1375:
1376: =pod
1377:
1378: =head2 SignalledToDeath
1379:
1380: Called in response to a signal that causes a chid process to die.
1381:
1382: =cut
1383:
1384:
1385: sub SignalledToDeath {
1386: my $event = shift;
1387: my $watcher= $event->w;
1388:
1389: Debug(2,"Signalled to death! via ".$watcher->data);
1390: my ($signal) = $watcher->data;
1391: chomp($signal);
1392: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1393: ."died through "."\"$signal\"");
1394: LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1395: ."\"$signal\"");
1396: exit 0;
1397:
1398: }
1399:
1400: =head2 ToggleDebug
1401:
1402: This sub toggles trace debugging on and off.
1403:
1404: =cut
1405:
1406: sub ToggleDebug {
1407: my $Current = $DebugLevel;
1408: $DebugLevel = $NextDebugLevel;
1409: $NextDebugLevel = $Current;
1410:
1411: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1412:
1413: }
1414:
1415: =head2 ChildProcess
1416:
1417: This sub implements a child process for a single lonc daemon.
1418:
1419: =cut
1420:
1421: sub ChildProcess {
1422:
1423:
1424: #
1425: # Signals must be handled by the Event framework...
1426: #
1427:
1428: Event->signal(signal => "QUIT",
1429: cb => \&SignalledToDeath,
1430: data => "QUIT");
1431: Event->signal(signal => "HUP",
1432: cb => \&ChildStatus,
1433: data => "HUP");
1434: Event->signal(signal => "USR1",
1435: cb => \&ChildStatus,
1436: data => "USR1");
1437: Event->signal(signal => "INT",
1438: cb => \&ToggleDebug,
1439: data => "INT");
1440:
1441: SetupTimer();
1442:
1443: SetupLoncListener();
1444:
1445: $Event::Debuglevel = $DebugLevel;
1446:
1447: Debug(9, "Making initial lond connection for ".$RemoteHost);
1448:
1449: # Setup the initial server connection:
1450:
1451: # &MakeLondConnection(); // let first work requirest do it.
1452:
1453:
1454: Debug(9,"Entering event loop");
1455: my $ret = Event::loop(); # Start the main event loop.
1456:
1457:
1458: die "Main event loop exited!!!";
1459: }
1460:
1461: # Create a new child for host passed in:
1462:
1463: sub CreateChild {
1464: my $sigset = POSIX::SigSet->new(SIGINT);
1465: sigprocmask(SIG_BLOCK, $sigset);
1466: my $host = shift;
1467: $RemoteHost = $host;
1468: Log("CRITICAL", "Forking server for ".$host);
1469: $pid = fork;
1470: if($pid) { # Parent
1471: $RemoteHost = "Parent";
1472: $ChildHash{$pid} = $RemoteHost;
1473: sigprocmask(SIG_UNBLOCK, $sigset);
1474:
1475: } else { # child.
1476: ShowStatus("Connected to ".$RemoteHost);
1477: $SIG{INT} = DEFAULT;
1478: sigprocmask(SIG_UNBLOCK, $sigset);
1479: ChildProcess; # Does not return.
1480: }
1481:
1482: }
1483: #
1484: # Parent process logic pass 1:
1485: # For each entry in the hosts table, we will
1486: # fork off an instance of ChildProcess to service the transactions
1487: # to that host. Each pid will be entered in a global hash
1488: # with the value of the key, the host.
1489: # The parent will then enter a loop to wait for process exits.
1490: # Each exit gets logged and the child gets restarted.
1491: #
1492:
1493: #
1494: # Fork and start in new session so hang-up isn't going to
1495: # happen without intent.
1496: #
1497:
1498:
1499:
1500:
1501:
1502:
1503: ShowStatus("Forming new session");
1504: my $childpid = fork;
1505: if ($childpid != 0) {
1506: sleep 4; # Give child a chacne to break to
1507: exit 0; # a new sesion.
1508: }
1509: #
1510: # Write my pid into the pid file so I can be located
1511: #
1512:
1513: ShowStatus("Parent writing pid file:");
1514: $execdir = $perlvar{'lonDaemons'};
1515: open (PIDSAVE, ">$execdir/logs/lonc.pid");
1516: print PIDSAVE "$$\n";
1517: close(PIDSAVE);
1518:
1519:
1520:
1521: if (POSIX::setsid() < 0) {
1522: print "Could not create new session\n";
1523: exit -1;
1524: }
1525:
1526: ShowStatus("Forking node servers");
1527:
1528: Log("CRITICAL", "--------------- Starting children ---------------");
1529:
1530: my $HostIterator = LondConnection::GetHostIterator;
1531: while (! $HostIterator->end()) {
1532:
1533: $hostentryref = $HostIterator->get();
1534: CreateChild($hostentryref->[0]);
1535: $HostIterator->next();
1536: }
1537: $RemoteHost = "Parent Server";
1538:
1539: # Maintain the population:
1540:
1541: ShowStatus("Parent keeping the flock");
1542:
1543: #
1544: # Set up parent signals:
1545: #
1546:
1547: $SIG{INT} = \&Terminate;
1548: $SIG{TERM} = \&Terminate;
1549: $SIG{HUP} = \&Restart;
1550: $SIG{USR1} = \&CheckKids;
1551:
1552: while(1) {
1553: $deadchild = wait();
1554: if(exists $ChildHash{$deadchild}) { # need to restart.
1555: $deadhost = $ChildHash{$deadchild};
1556: delete($ChildHash{$deadchild});
1557: Log("WARNING","Lost child pid= ".$deadchild.
1558: "Connected to host ".$deadhost);
1559: Log("INFO", "Restarting child procesing ".$deadhost);
1560: CreateChild($deadhost);
1561: }
1562: }
1563:
1564:
1565:
1566: =pod
1567:
1568: =head1 CheckKids
1569:
1570: Since kids do not die as easily in this implementation
1571: as the previous one, there is no need to restart the
1572: dead ones (all dead kids get restarted when they die!!)
1573: The only thing this function does is to pass USR1 to the
1574: kids so that they report their status.
1575:
1576: =cut
1577:
1578: sub CheckKids {
1579: Debug(2, "Checking status of children");
1580: my $docdir = $perlvar{'lonDocRoot'};
1581: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
1582: my $now=time;
1583: my $local=localtime($now);
1584: print $fh "LONC status $local - parent $$ \n\n";
1585: foreach $pid (keys %ChildHash) {
1586: Debug(2, "Sending USR1 -> $pid");
1587: kill 'USR1' => $pid; # Tell Child to report status.
1588: sleep 1; # Wait so file doesn't intermix.
1589: }
1590: }
1591:
1592: =pod
1593:
1594: =head1 Restart
1595:
1596: Signal handler for HUP... all children are killed and
1597: we self restart. This is an el-cheapo way to re read
1598: the config file.
1599:
1600: =cut
1601:
1602: sub Restart {
1603: KillThemAll; # First kill all the children.
1604: Log("CRITICAL", "Restarting");
1605: my $execdir = $perlvar{'lonDaemons'};
1606: unlink("$execdir/logs/lonc.pid");
1607: exec("$execdir/lonc");
1608: }
1609:
1610: =pod
1611:
1612: =head1 KillThemAll
1613:
1614: Signal handler that kills all children by sending them a
1615: SIGHUP. Responds to sigint and sigterm.
1616:
1617: =cut
1618:
1619: sub KillThemAll {
1620: Debug(2, "Kill them all!!");
1621: local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
1622: foreach $pid (keys %ChildHash) {
1623: my $serving = $ChildHash{$pid};
1624: Debug(2, "Killing lonc for $serving pid = $pid");
1625: ShowStatus("Killing lonc for $serving pid = $pid");
1626: Log("CRITICAL", "Killing lonc for $serving pid = $pid");
1627: kill 'QUIT' => $pid;
1628: delete($ChildHash{$pid});
1629: }
1630: my $execdir = $perlvar{'lonDaemons'};
1631: unlink("$execdir/logs/lonc.pid");
1632:
1633: }
1634:
1635: =pod
1636:
1637: =head1 Terminate
1638:
1639: Terminate the system.
1640:
1641: =cut
1642:
1643: sub Terminate {
1644: KillThemAll;
1645: Log("CRITICAL","Master process exiting");
1646: exit 0;
1647:
1648: }
1649: =pod
1650:
1651: =head1 Theory
1652:
1653: The event class is used to build this as a single process with an
1654: event driven model. The following events are handled:
1655:
1656: =item UNIX Socket connection Received
1657:
1658: =item Request data arrives on UNIX data transfer socket.
1659:
1660: =item lond connection becomes writable.
1661:
1662: =item timer fires at 1 second intervals.
1663:
1664: All sockets are run in non-blocking mode. Timeouts managed by the timer
1665: handler prevents hung connections.
1666:
1667: Key data structures:
1668:
1669: =item RequestQueue
1670:
1671: A queue of requests received from UNIX sockets that are
1672: waiting for a chance to be forwarded on a lond connection socket.
1673:
1674: =item ActiveConnections
1675:
1676: A hash of lond connections that have transactions in process that are
1677: available to be timed out.
1678:
1679: =item ActiveTransactions
1680:
1681: A hash indexed by lond connections that contain the client reply
1682: socket for each connection that has an active transaction on it.
1683:
1684: =item IdleConnections
1685:
1686: A hash of lond connections that have no work to do. These connections
1687: can be closed if they are idle for a long enough time.
1688:
1689: =cut
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