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